Python code continues running even after finishing on Ubuntu

Question

I am running Python 3.9.12 on Ubuntu 16.04 using an Anaconda environment. I've found that all my scripts don't finish whenever they reach the end of execution, as in, they do not exit with code 0.

Example:

print("Hello World")

Even this simple one-liner will continue to run forever without exiting unless I explicitly do:

print("Hello World")
exit(0)

I'm unsure whether this is due to Ubuntu 16.04, some specific settings on the computer I'm using, or some other reason. It has never happened to me before across other computers and operating systems, where the normal expected behavior is that Python automatically terminates with exit code 0 on the end of the program.