How can I fix this? My apple thread network seems to have split from HA

I’m not sure how this happened or why, but my two HomePods used to be apart of my preferred thread network. Now I can’t figure out how to get them to join it again, they used to be in it. Now it’s just my Apple TV joined in with it. Haven’t noticed any issues at all, but I would like to know if anyone else has had this happen?