https://www.mangago.me/home/mangatopic/21080691/
Here is a explanation why they are gone for a moment. I was also very surprised but now relieved. Hope it will help you ;>
The list we make ourselves, and the Bookmarks we made are all unaffected. All the Reading list are gone, as well as the Comments we made on that Tag screen pop-up (where we mark our books).
The only ones that are restoring, are tagged and rated books. The non-rated and non-tagged are for the most committed. Plus the majority are placed at the wrong "Want to Read", as it should be on the "Reading/Already Read". The maintenance is still ongoing. So it's far from being fixed yet (Since January 27)
My account is made in 2015, and supposed have added 5000+. Only like 20% came back besides those I added/re-added myself, but unfortunately I didn't tagged nor rated a lot of them. (I'm starting to loose hope of getting everything back, especially the comments that I made as notes for myself, little by little by the day.)
https://www.mangago.me/home/mangatopic/21080691/
Basically we need to wait. I'm lucky to have my "want to read" and "already read" lists back again already but my "reading" list is still empty and all the restored mangas are still missing the notes I wrote.
Honestly, this site probably has thousands of users who have thousands of mangas saved, which is now being restored by only a few admins/mods. Of course they're gonna be slow.
So let's just wait another week or so before we panic because every email we send them will most likely slow down the process further. Until then, let's have full confidence that everything will come back as it was (๑•ㅂ•)و✧
Oh, and here you can read the update of the situation: https://www.mangago.me/home/mangatopic/21092806/
(1st Run is done). We now on 2nd run

Ive been using this web for almost 5 years. Seen it go down many times and its always okay in the end but its my first time noticing my titles are gone. From what i understood so far, lists are coming back. I don't really use lists i have one and it's been restored.
I mostly add my mangas, webtoons, etc. to "want to read" "reading" "have read". I currently have the read ones. But the ones I've been letting marinate are gone.
Will they be restored too like lists or are they gone for good?? And is anyone else having this specific issue?
Tnx to anyone who has an answer.