Help me in solving PASSWD problem

My issue

When I’m pressing the “Debug my code” button, I’m getting a blank screen instead of seeing the failed test case.

My code

import re

t = int(input())

for _ in range(t):
    s = input()
    valid = "YES"
    # lower case characters should be present
    x ="[a-z]", s)
    if not x:
        valid = "NO"
    #number of characters is more than 9
    if len(s) < 10:
        valid = "NO"
    # Digits are strictly inside all the other characters
    y ="\D+[0-9]\D+", s)
    if not y:
        valid = "NO"
    # Must have one uppercase character strictly inside
    z =".+[A-Z].+", s)
    if not z:
        valid = "NO"
    # Must have one of the given special characters, strictly inside
    a =".+[@#%&?].+", s)
    if not a:
        valid = "NO"

Learning course: Level up from 1* to 2*
Problem Link: CodeChef: Practical coding for everyone

Is it still happening ??

No, not happening anymore. Not sure what caused it in the first place.