Okay so... The first thing you've done wrong is to use recursion to repeat the program: https://en.wikipedia.org/wiki/Recursion .
By default in python, a function returns 'None':

>>> def f():
...     x = 0
... 
>>> print(f())
None

see https://realpython.com/python-return-statement/ .
And in a whileloop None is considered as False as it is not True .
So when your function ends here after the execution of repeat :

...
    else:
        repeat()

the function returns None value instead of True , and therefore the while loop ends.
You should instead use :

...
else:
    return repeat()

which will return what repeat() returns (True in case of the following answer "yes").
However I would have not done the program like this.

def repeat():
    r = True
    while r:
       ques = input(...).lower()
       if ques == "no":
           r = False

which avoids useless recursion issues.
Have a nice day :)