Drawing edits disappear once I playback

I opened a file I was working on the other night, to go and clean up lines and whatnot; I can edit the frames just fine, and the lines look like I need them to, however when I push play all the changes I just made disappear. Animate is on, using the same settings I was using the other night, and I didn’t have this problem before. Anyone know how to fix this?

I assume you saved the project before hitting play?

Post some screenshots to a file-hosting service and provide the links.
It’s not clear from your description what’s going on.