There is a strange thing between C++14 and C++20

We can see that the down two code are same, but the code using C++20 got TLE, and the code using C++14 got AC

https://mirror.codeforces.com/contest/1634/submission/145631828

https://mirror.codeforces.com/contest/1634/submission/145633066

We can also see that the down two code are same, but the code using C++14 got TLE, and the code using C++20 got AC

https://mirror.codeforces.com/problemset/submission/573/145373496

https://mirror.codeforces.com/problemset/submission/573/145372752

What's wrong with it? It there anyone could help me answer the question? Many Thanks!