trouble joining worlds

whenever I try to join my friend, or when they try to join me, we cannot find each others world. it is definitely on their end, because another friend had the same problem with their worlds, and we can’t find anything wrong. all 3 of us are logged into our Xbox Live accounts, and we all have the latest software update and Minecraft update. whenever I try to invite them into my world by searching their Gamertag, it either says they’re offline or on the Xbox app, even when they’re in Minecraft. we all have our privacy settings set so we could join each other, and it was working fine up until yesterday. the images below are on their screen.