Yeah, post a video for sure. Before and after would be great if you could do it that way, if not, that is cool too.
Things like stride length are the results of other things happening (or not happening) earlier in the delivery. You sound tentative to me.
My son injured his back last year in college, was misdiagnosed by a well intentioned but general incompetent "training staff" and it affected his performance and he was cut. He took a couple months off while his back got better/treated. He came back throwing 78 mph, he was sitting 81-82 ish before. Drops can happen, but, any drop from a 3 month lay off should be recaptured relatively quickly I would think. Since then he has trained and is sitting 83 or so touching 85, hoping for more gains before next season starts.
Here is the thing. Before his senior year of high school he hurt his elbow. He was able to play, but, ended up guiding the ball in. His mechanics changed (he was finishing upright, not being explosive etc) subconsciously because he was working from a point of weakness. He didn't think his mechanics changed, but, his location went away and velo dropped. It was work to get that restored and improved.
Will be interesting to see what video shows.