Python time.sleep(1) raises TypeError?

Question

I get this strange behaviour (random TypeError exception is thrown) whenever I interrupt/kill a sleeping parent thread from a child thread in python 3 but the strange behaviour ONLY appears if the python script was initiated by a shell script with an & argument to make it run in the background.

So here's the minimum reproducible python code I could come up with that can trigger this issue.

User@MSI: ~/test $ cat m.py

import threading
import _thread
import time


def child_thread():
    time.sleep(1)
    print('child interrupting parent')
    _thread.interrupt_main()
    
if __name__ == '__main__':
    t = threading.Thread(target=child_thread, args=())
    t.start()
    print('parent looping')
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        print('caught interruption raised from user or child thread :)')
    except TypeError as e:
        print('why would I ever catch a TypeError?')
        raise
    except Exception as e:
        print('Strange Exception Received ')
        raise

It's a very simple script where a parent initiates a child thread and then loops forever and the child thread (after 1 second) interrupts the main thread which SHOULD raise a KeyboardInterruption towards the main thread.

Now if I invoke my script using a bash script with the background flag & at the end, (the below output makes no sense)

User@MSI: ~/test $ cat ./m.sh
#!/bin/bash
python3 m.py &

User@MSI: ~/test $ ./m.sh
parent looping
child interrupting parent
why would I ever catch a TypeError?
Traceback (most recent call last):
  File "m.py", line 17, in <module>
    time.sleep(1)
TypeError: 'int' object is not callable

below I show the output of my script behaving completely normal when I run it from

1. From the terminal
2. From the terminal with &
3. From the bash script (without &)

And all three behave as expected... (the below output is as expected)

User@MSI: ~/test $ python3 m.py
parent looping
child interrupting parent
caught interruption raised from user or child thread :)

Same result when running it in the background with & (the below output is as expected)

User@MSI: ~/test $ python3 m.py &
[1] 5884
parent looping
child interrupting parent
caught interruption raised from user or child thread :)

[1]+  Done   python3 m.py

And even from a one line script called m.sh that executes m.py (the below output is as expected)

User@MSI: ~/test $ cat m.sh
#!/bin/bash
python3 m.py

User@MSI: ~/test $ ./m.sh
parent looping
child interrupting parent
caught interruption raised from user or child thread :)

I'm completely dumbfounded and have no idea what time.sleep and TypeErrors have to with how I invoked my script and specifically invoking it from a shell script and from the backgrounded. This is one of the strangest errors I've encountered.

If it matters, I'm running Python 3.6.12 and Debian 9.12

I hope someone can figure this out.

EDIT: Here are comparisons of the bytecode for the buggy version's (run from shell script with &) output And here's the good version's (run from terminal) output

And for easy comparison, here's a diff of the bytecode. The only difference is the location of the child thread in memory.