Ghost read chapters? bug/feature/hack? (this is not clickbait btw)

[wazup10]

so uh ive been away for 2 weeks and was looking forward to reading all the piled up manga, but then i go into follows and get sent to the follows-reading section. The worst part is that i go into the follows main section and find that some of the mangas have their chapters already read... mind you i havent logged on to mangadex in 2 weeks...
So i dont know whether its a bug/feature/someone accessed my account whilst i was gone.
I havent shared my account to anyone btw

edit: ah wait im just stupid... its a feature of when you set the follow to completed, all the newly released chapters say they have been read