why my "I'm reading" list become I already read" collection TT

As far as what I read in the FAQs there's a specific order.
Already read > Reading > Want to read
Some users will find their reading or want to read are in the read list now (like in my case.) I'm sure something will be sorted after the initial restoration happens.
https://www.mangago.me/home/mangatopic/21080691/

ohh thank you so much, thought I have to rearrange it back

I wouldn't change anything just yet, in case there's anymore glitches etc that may impact what manga are restored when you change them manually. People have been advised to be patient for the time being while everything is sorted, and after everything is restored and the lists are back up and running, if your lists are still not returned to normal - only then should you contact the email in the FAQs (to save them from being spammed)