My first time playing Fifa online in a very long time and I was astounded by the shear number of people using cheats.
I was repeatedly tackling players but because they are using a cheat, the ball just springs straight back to them. This wasn't a one off incidence, it would happen repeatedly in many games.
I did my due diligence in this issue and according to the official EA November pitch notes, the Fifa 20 tackling mechanic involves the tackled player stumbling during which time that tackled player is no longer able to take control of the ball.
That is certainly the mechanic that effects my players when they are tackled, so if my opponents were somehow able to bypass this in-game mechanic, they were clearly cheating. There is no bug report on this issue with a response from an EA rep and no other communication from EA concerning this other than the November pitch notes, so cheating is clearly the only conclusion.
The 2nd cheat I experienced was my controls simply being overridden. I could be inputting a direction for a pass but rather than follow my input, my player would often simply pass the ball in a completely different direction, directly to the other team. As with my first complaint, I could find no official communication relating to if this was a bug so again, it appears to be a common use of a cheat.
Fifa has no in-game method to report cheating (rather suspiciously) so the only option was to report the cheating via the Xbox console directly. Cheating in games very rarely goes punished but if you experience these I would encourage you to submit the necessary report anyway.