Browsing zim wiki files on ios app crashes server

i sync zim wiki files on my nextcloud. when i try to open a single zim wiki .txt file thru the nc ios client, i get red bar errors at top of screen. i checked how the server is going via htop/logs, and basically merely attempting to open this simple text file overloads the server and it starts killing processes like mysql to stay afloat…

i have no sense of why it does this. opening other files on nc ios is no prob, and zim only creates simple txt files. i also don’t have 0000000s of files in zim, only a few hundred, mayb 20MB worth so far…

the server normally runs at 50% ram.

any pointers wd be appreciated.