answer:Facebook has cut back a lot of newsfeed access for groups as a way of prioritizing those who spend money for better newsfeed visibility. This didn’t affect everyone and everything at the same time, it seems to be trickling through the community at large. I noticed it about two months after I saw my friends complaining about it, for example. I have heard that you can improve the visibility of these groups in your newsfeed by commenting on posts on their pages (not really enough to just “like” posts), but I haven’t tried this myself. Anyway, I don’t know if that’s what is causing your situation, but it’s one idea.