It happened during a shutdown unfortunately some people forever lost their readings with no way to get them back :(
You can't report it because it happened to all of us back in January. Mangago's data disk crashed. Only stories you have rated and/or tagged were recovered, nothing else did or will come back. All retrieved stories were dumped into your "Already read" list, you have to manually re-add them back where they were pre-crash. You can start rebuilding your lists now.
You can use an e-mail to contact and try to solve it; however I do not know if it might be helpful, when I tried back then they replied, hope you have more luck than me! [email protected]
can sm1 show me how to report a problem? i had a time period where i stopped reading manga and recently i got back to reading manga, and saw like 30% of my “readings” disappeared