I was playing on a server running the R.A.D. mod pack: https://www.curseforge.com/minecraft/modpacks/roguelike-adventures-and-dungeons
Last night I gained max hearts before the host's computer auto-updated, killing the server. Today I came back on to find that I was missing three & a half hearts from the max, & now I can't regain them.

Did you ever find a solution to this?