recently I started to feel stuck on the easy problems that I've used to solve them easily on the same rating

like last contest 1300 was harder than old ones(I solve 1300 problems easily), and I think Codeforces problems are being guessing a solution or am I wrong I don't know or maybe the problems with same rating are getting harder because now I tried to solve not very old but not new problems and solved them but new ones there are something weird about them and there is a friend of mine who told that the new problems are being written a way that AI can't solve is that true.

if anyone knows why is that happening please tell me(do not judge me based on my rating)

thank you

P.S. forgive my poor English ^_^