Some threads drop off multi/ view

I mostly use https://thread.zone/multi/

and i’ve noticed occasionally i’ll be like oh yeah i want to post in this old thread, but I don’t see it on multi/ (and it shows threads from 2017 on the first screen)

But then if I search in the zone it pops up, and sometimes there are even new posts i hadn’t seen. and then if I post in it, then it shows up on multi/ again.

idk maybe i’m missing something and this is how it’s supposed to work? i can post examples here if that’d be helpful

ohhhhh ok. thanks. i think what i want is multi/subscribed then