Pipe dream, but I really wish we would make it illegal to use the terms "Buy" or "Own" for digital goods that can at some point not exist outside of your control.
I give you a dollar and get a DRM-free video file? That is buying.
I give you a dollar and can watch a video file an unlimited number of times in your app? That is not buying, and it should be fraud to claim that it is.
I'm in the same boat - zero ads in Sync for Lemmy until this last update. I just assumed the purchase from Sync for Reddit had carried over, but I guess either LJ changed his mind or it wasn't intentional.