Input() suddendly needs more than 1 Enter press to resume execution

Question

This is the first time i faced this problem. It's pretty hard to pinpoint where is the cause since i'm using a lot of libraries in my project.. By the way, this is what it looks like:

# a LOT of stuff
f = Foo()
print('f initialized')
input('Waiting for user input to resume) 
print('Resumed!') # This is not printed until i press Enter 2 times, instead of 1.

Has anyone ever encountered anything like this?

I've also tried setting up a different Venv with no luck.

BTW i'm running python3.7 in Windows