Maybe it's time you stopped doing sets across, and did ramping sets.
Some change and less adherence to a prescribed dictated protocol, may do you some good.
What Oscar said, except maybe not particularly ramping sets.
Why should every set be the same reps?
Why should every rep be the same load?
The reason people stall on routines like StrongLifts or Starting Strength isn't all the recovery mumbo jumbo that their authors put out, they stall because the routines add work faster than the human body can gain strength. Eventually the work catches up with your strength gain, and you can't keep doing it. Doing 5x5 is, obviously, 25 reps. Adding even 5 pounds to each of 25 reps is a huge increase in work load. So why not just add a rep to one or two of the sets? Why not just increase the weight for one of the sets, and not necessarily the last one? Starting with 5 sets, I don't like to add sets, but especially if you are doing fewer sets, it's easy at some point just to add a set, and maybe not even as big a set as the others. Deciding "I'm doing 5x5" or "I'm doing 3x8" locks you into a rigid routine that you don't need to be in. You could do sets of 5,7,5. Maybe next time do 5,7,7 and next time add weight to the middle set. Or if you finish your 3 sets, and you feel like you still have something left, throw in another set. Or do your 3 sets with whatever weight, then throw on 10 or 15 pounds and do a single. Once you break out of the XbyX prison, you're free to progress as your body wants to progress. But you have to be thinking all the time, and that's hard for some of us. But if an old dog like me can learn, so can you!
By the way, if you have been doing this sort of progression for a while, you end up with bigger and bigger sets, and more and more sets. At some point you have to take the reps and sets back down to something simple, but now at a higher intensity than before, and start working things up again.