There appears to be a problem with players 'ghosting' or just passing through other players (principally ball carriers) as though the opposing player doesn't exist.
In the early days of computing when this happened in simulations it was usually a framerate problem, i. e. the computer's processor was operating at too slow a speed to properly compute the intersections of moving objects ("sprites" in those good old days) in enough time to detect, calculate, and resolve the interactions between them. I wonder if that is still the case with the multi gigahertz processors of today. (?)
It seems silly and forms a bad impression when players pass directly through the visual midlines of opposing ball carriers (like Casper the friendly ghost) with no effect whatsoever.
Even if player cannot tackle and is a lousy defender there is the real-life consideration that the oponent's body is actually there amd there should be some bumping and consequent slowing down of ball carriers even with missed tackles.
The constant invisible pass-throughs without effect looks very unrealistic and makes an unsatisfactory impression.
Football is a collision sport not a dance of pixies or hummingbirds or some such thing.