I have no idea what your issue is, but I did have a massive RC repair and did a good job of rehabbing it. Major takeaway point is that things like ITYs (https://www.youtube.com/watch?v=owOtS66Omxw -- this does W's adn L's which I didn't need) and kettlebell armbars and screwdrivers (https://www.youtube.com/watch?v=qvYKRyFeSDc) were the best. Make sure you read up on correct form, in particular packing the shoulder. Form, form and did I say form? Above all, the arm is stick and the muscles in the shoulder and upper back will be doing the work.
Why? As explained to me by my excellent rehab coach, the rotator cuff is mis-named. It can assist with rotating the arm, but in actuality, its job is to oppose the tendency of the deltoids to pull the humeral head (slightly) out of the sockets. As such, it is not possible to fire a single RC muscle in practice and a lot of RC rehab (like any isolation exercises) introduces significant strength imbalances. They get the individual muscles stronger but that is not useful strength. I had lots of random pains until I just hunkered down and did these exercises religiously for a couple of months. The aim with these is to get all of the RC muscles firing correctly and balancing each other out, as well as to get a feel for having the shoulder seated right in the socket. In any case, if you haven't done these, I found them time well spent post-op.