By some "pattern/general idea" of how should work.

And, it first, the company stared to underpay me almost 1/3 part of what's supposed to be ~ 2 moths ago without saying a word.

I do agree that there was a moment when I started working little less productive. That's cos my parent had a stage 4 cancer. Treatment started helped a little and I'am became better ~ 3 weeks ago when I only had a suspicion that I am underpaid.