My rating don't change

Hi !
Since I'm back in lichess, I played some rated games without changing my rating.

Is it normal ?

It certainly is not. Your profile states:

This player artificially increases/decreases their rating

That should be the problem here..

I didn't do anything like that :) . Just stopped playing during some months.

How can I fix this problem ?

Well then I suggest you read this:
en.lichess.org/qa/258/all-about-cheating-questions-and-answers

and in case it really does not apply on you contact:
lichess.contact@gmail.com

Good luck!