Sometimes it need authentication (microsoft) when join realm

_Hi.. When I join my own realm, sometimes it say "You need microsoft authentication.. bla..bla..bla..." Is this Microsoft problem or this error is from Minecraft.. I just dont know.. Please help.. I'm confusing.. _

Update

I know i just need to log out mocrosoft and restart minecraft. Then I can join back but.. this message sometimes appear in screen when im start join..