I find backing tracks hard to play along with for much the same reason. A lot of parts are fairly repetitive and I don't want to count the bars if I don't have to.
I find it's mostly because there are no vocals. When jamming with buddies or playing cds it's much easier as the words help tell you where you are in the song and when to change. Singing along would probably help. I haven't tried this as I have an agreement with the local law enforcement specialists not to sing, lol.
Listening to the drum beat should help cause often they do a splash or something right before the change to the chorus.
On the other hand it could be because we're getting older.
