The site crashed a few weeks back and some accounts had their lists restored. Mine was partially restored and my reading/want to read is currently jumbled. Unsure if it'll be fixed, praying time will resolve it though. Good luck finding your series! If you remember any details about them you can make a new thread and someone might recognize/be able to point you in the right direction.
omg I lost everything too what;-;
More information through these links here
Sadly, it's been confirmed only tagged/rated works will be returning to your lists
About Lists
https://www.mangago.me/home/mangatopic/21155166/
Latest Update + Don't mess with lists yet
https://www.mangago.me/home/mangatopic/21212683/
https://www.mangago.me/home/mangatopic/21213931/
FAQs at time of site crash
https://www.mangago.me/home/mangatopic/21080691/
I been log out of my account and when I log back on all my reading list was gone. And it took my 3/4 year to built this list and adding more. I dont even remember them all. ╥﹏╥