Spell Shortenings AC in Python3 but TLE in Pypy3

cook your dish here

for _ in range(int(input())):
n=int(input())
s=input()
f=0
e=“”
for i in range(n-1):
if s[i]>s[i+1] and f==0: f=1
else: e+=s[i]
if f==1: e+=(s[-1])
print(e)

The same code Submitted in python3 gives AC and pypy3 gives TLE for spell shortenings problem.
Most of the problems pypy3 was faster but for this problem python3 is faster.
What’s issue happening?

It’s sometimes, faster it’s normal see pluse, you use C++17 anyway: