[Can't invite friends]

The same thing happened to me but it happened when i got done with the war within  quest and it has been weeks that i tried to find ways to fix the issue. Some people in the warframe community (which are very nice people that  tried to help) did not know about the offline bug. for some odd reason  all of my friends it says i'm offline and they are offline to so i'm kinda stuck doing missions solo for a while even if the thing is on public the sad thing is i cant even do sanctuary onslaught ( I'm trying to get to mastery rank 12)

sorry if my grammar is bad