Sometimes having such behaviours can be caused by having other toxic teammates.
Its not because you're banned that you're not toxic, for example
Its a good day, you take a coffee and start csgo, you're happy.
You start a MM match and then you lose a clutch in a gunround situation, then a guy starts telling that you're shit etc.. And start tking you in the next round, him and his friends pisses you off during the entire half, annoying you whatever and then you start to tk them too, boom ban.
Sometime a good smiling guy can turn shit and toxic because of other toxic people, being toxic is like a disease, it spreads.
Inb4 "just ignore lmao"
We're humans, not robots, everyone has been toxic at least once in the game.