What exactly is the abnormalities that causes me to get banned?

My main account was banned for a week, got unbanned Saturday played 1, ONE match only then got banned for 1 week again.

My second account I was playing with no problem for a week then got banned for a month? Tf? What's the problem? This all started this szn, I am writing this same thing on discord and nobody gaf (I am not using hacks or roots)