Solvedairflow scheduler gets stuck without a trace

Process 132: /usr/local/bin/python /usr/local/bin/airflow scheduler
Python v3.8.3 (/usr/local/bin/python)
Thread 132 (idle): "MainThread"
  _send (multiprocessing/connection.py:368)
      Arguments::
          self: <Connection at 0x7f5db7aac550>
          buf: <bytes at 0x5564f22e5260>
          write: <builtin_function_or_method at 0x7f5dbed8a540>
      Locals::
          remaining: 1213
  _send_bytes (multiprocessing/connection.py:411)
      Arguments::
          self: <Connection at 0x7f5db7aac550>
          buf: <memoryview at 0x7f5db66f4a00>
      Locals::
          n: 1209
          header: <bytes at 0x7f5dbc01fb10>
  send (multiprocessing/connection.py:206)
      Arguments::
          self: <Connection at 0x7f5db7aac550>
          obj: <TaskCallbackRequest at 0x7f5db7398940>
  send_callback_to_execute (airflow/utils/dag_processing.py:283)
      Arguments::
          self: <DagFileProcessorAgent at 0x7f5db7aac880>
          request: <TaskCallbackRequest at 0x7f5db7398940>
  _process_executor_events (airflow/jobs/scheduler_job.py:1242)
      Arguments::
          self: <SchedulerJob at 0x7f5dbed3dd00>
          session: <Session at 0x7f5db80cf6a0>
      Locals::
          ti_primary_key_to_try_number_map: {("redeacted", "redeacted", <datetime.datetime at 0x7f5db768b540>): 1, ...}
          event_buffer: {...}
          tis_with_right_state: [("redeacted", "redeacted", <datetime.datetime at 0x7f5db768b540>, 1), ...]
          ti_key: ("redeacted", "redeacted", ...)
          value: ("failed", None)
          state: "failed"
          _: None
          filter_for_tis: <BooleanClauseList at 0x7f5db7427df0>
          tis: [<TaskInstance at 0x7f5dbbfd77c0>, <TaskInstance at 0x7f5dbbfd7880>, <TaskInstance at 0x7f5dbbfdd820>, ...]
          ti: <TaskInstance at 0x7f5dbbffba90>
          try_number: 1
          buffer_key: ("redeacted", ...)
          info: None
          msg: "Executor reports task instance %s finished (%s) although the task says its %s. (Info: %s) Was the task killed externally?"
          request: <TaskCallbackRequest at 0x7f5db7398940>
  wrapper (airflow/utils/session.py:62)
      Locals::
          args: (<SchedulerJob at 0x7f5dbed3dd00>)
          kwargs: {"session": <Session at 0x7f5db80cf6a0>}
  _run_scheduler_loop (airflow/jobs/scheduler_job.py:1386)
      Arguments::
          self: <SchedulerJob at 0x7f5dbed3dd00>
      Locals::
          is_unit_test: False
          call_regular_interval: <function at 0x7f5db7ac3040>
          loop_count: 1
          timer: <Timer at 0x7f5db76808b0>
          session: <Session at 0x7f5db80cf6a0>
          num_queued_tis: 17
  _execute (airflow/jobs/scheduler_job.py:1280)
      Arguments::
          self: <SchedulerJob at 0x7f5dbed3dd00>
      Locals::
          pickle_dags: False
          async_mode: True
          processor_timeout_seconds: 600
          processor_timeout: <datetime.timedelta at 0x7f5db7ab9300>
          execute_start_time: <datetime.datetime at 0x7f5db7727510>
  run (airflow/jobs/base_job.py:237)
      Arguments::
          self: <SchedulerJob at 0x7f5dbed3dd00>
      Locals::
          session: <Session at 0x7f5db80cf6a0>
  scheduler (airflow/cli/commands/scheduler_command.py:63)
      Arguments::
          args: <Namespace at 0x7f5db816f6a0>
      Locals::
          job: <SchedulerJob at 0x7f5dbed3dd00>
  wrapper (airflow/utils/cli.py:89)
      Locals::
          args: (<Namespace at 0x7f5db816f6a0>)
          kwargs: {}
          metrics: {"sub_command": "scheduler", "start_datetime": <datetime.datetime at 0x7f5db80f5db0>, ...}
  command (airflow/cli/cli_parser.py:48)
      Locals::
          args: (<Namespace at 0x7f5db816f6a0>)
          kwargs: {}
          func: <function at 0x7f5db8090790>
  main (airflow/__main__.py:40)
      Locals::
          parser: <DefaultHelpParser at 0x7f5dbec13700>
          args: <Namespace at 0x7f5db816f6a0>
  <module> (airflow:8)

Process 134: airflow scheduler -- DagFileProcessorManager
Python v3.8.3 (/usr/local/bin/python)
Thread 134 (idle): "MainThread"
  _send (multiprocessing/connection.py:368)
      Arguments::
          self: <Connection at 0x7f5db77274f0>
          buf: <bytes at 0x5564f1a76590>
          write: <builtin_function_or_method at 0x7f5dbed8a540>
      Locals::
          remaining: 2276
  _send_bytes (multiprocessing/connection.py:411)
      Arguments::
          self: <Connection at 0x7f5db77274f0>
          buf: <memoryview at 0x7f5db77d7c40>
      Locals::
          n: 2272
          header: <bytes at 0x7f5db6eb1f60>
  send (multiprocessing/connection.py:206)
      Arguments::
          self: <Connection at 0x7f5db77274f0>
          obj: (...)
  _run_parsing_loop (airflow/utils/dag_processing.py:698)
      Locals::
          poll_time: 0.9996239839999816
          loop_start_time: 690.422146969
          ready: [<Connection at 0x7f5db77274f0>]
          agent_signal: <TaskCallbackRequest at 0x7f5db678c8e0>
          sentinel: <Connection at 0x7f5db77274f0>
          processor: <DagFileProcessorProcess at 0x7f5db6eb1910>
          all_files_processed: False
          max_runs_reached: False
          dag_parsing_stat: (...)
          loop_duration: 0.0003760160000183532
  start (airflow/utils/dag_processing.py:596)
      Arguments::
          self: <DagFileProcessorManager at 0x7f5dbcb9c880>
  _run_processor_manager (airflow/utils/dag_processing.py:365)
      Arguments::
          dag_directory: "/code/src/dags"
          max_runs: -1
          processor_factory: <function at 0x7f5db7b30ee0>
          processor_timeout: <datetime.timedelta at 0x7f5db7ab9300>
          signal_conn: <Connection at 0x7f5db77274f0>
          dag_ids: []
          pickle_dags: False
          async_mode: True
      Locals::
          processor_manager: <DagFileProcessorManager at 0x7f5dbcb9c880>
  run (multiprocessing/process.py:108)
      Arguments::
          self: <ForkProcess at 0x7f5db7727220>
  _bootstrap (multiprocessing/process.py:315)
      Arguments::
          self: <ForkProcess at 0x7f5db7727220>
          parent_sentinel: 8
      Locals::
          util: <module at 0x7f5db8011e00>
          context: <module at 0x7f5dbcb8ba90>
  _launch (multiprocessing/popen_fork.py:75)
      Arguments::
          self: <Popen at 0x7f5db7727820>
          process_obj: <ForkProcess at 0x7f5db7727220>
      Locals::
          code: 1
          parent_r: 6
          child_w: 7
          child_r: 8
          parent_w: 9
  __init__ (multiprocessing/popen_fork.py:19)
      Arguments::
          self: <Popen at 0x7f5db7727820>
          process_obj: <ForkProcess at 0x7f5db7727220>
  _Popen (multiprocessing/context.py:276)
      Arguments::
          process_obj: <ForkProcess at 0x7f5db7727220>
      Locals::
          Popen: <type at 0x5564f1a439e0>
  start (multiprocessing/process.py:121)
      Arguments::
          self: <ForkProcess at 0x7f5db7727220>
  start (airflow/utils/dag_processing.py:248)
      Arguments::
          self: <DagFileProcessorAgent at 0x7f5db7aac880>
      Locals::
          mp_start_method: "fork"
          context: <ForkContext at 0x7f5dbcb9ce80>
          child_signal_conn: <Connection at 0x7f5db77274f0>
          process: <ForkProcess at 0x7f5db7727220>
  _execute (airflow/jobs/scheduler_job.py:1276)
      Arguments::
          self: <SchedulerJob at 0x7f5dbed3dd00>
      Locals::
          pickle_dags: False
          async_mode: True
          processor_timeout_seconds: 600
          processor_timeout: <datetime.timedelta at 0x7f5db7ab9300>
  run (airflow/jobs/base_job.py:237)
      Arguments::
          self: <SchedulerJob at 0x7f5dbed3dd00>
      Locals::
          session: <Session at 0x7f5db80cf6a0>
  scheduler (airflow/cli/commands/scheduler_command.py:63)
      Arguments::
          args: <Namespace at 0x7f5db816f6a0>
      Locals::
          job: <SchedulerJob at 0x7f5dbed3dd00>
  wrapper (airflow/utils/cli.py:89)
      Locals::
          args: (<Namespace at 0x7f5db816f6a0>)
          kwargs: {}
          metrics: {"sub_command": "scheduler", "start_datetime": <datetime.datetime at 0x7f5db80f5db0>, ...}
  command (airflow/cli/cli_parser.py:48)
      Locals::
          args: (<Namespace at 0x7f5db816f6a0>)
          kwargs: {}
          func: <function at 0x7f5db8090790>
  main (airflow/__main__.py:40)
      Locals::
          parser: <DefaultHelpParser at 0x7f5dbec13700>
          args: <Namespace at 0x7f5db816f6a0>
  <module> (airflow:8)