Here’s the reply I received from “support” when I complained about the fact that I have 33 goals in league matches and 3 or fewer assists:
We appreciate the feedback on assists too, although it is a bit of a complex issue. The match algorithm applies certain criteria when simulating an assist scenario that must be met in order to qualify the pass as an actual assist. In real football, this translates to given specific conditions, like a direct pass for example. Not quite sure how this is formulated in-game, but we can guarantee that any situations considered as assists will be accounted for. One thing worth noting is that even when observing an animated assist during a live match, the pass may not be considered an actual assist by the system, as there are certain algorithm calculations which the live match animation can not fully recreate. I'd suggest not overthinking this, as the best approach you can take here is, and always has been, to focus on your player's passing skills to achieve a higher assist rate. I hope this provides some insight into the matter!