Minecraft Java Edition is the ONLY game I am having issues with.
(I don't play Bedrock and have never been interested in it).
This specifically includes a few STEAM games (which you folks don't control, but have a similar "online verification of ownership" setup).
Have gone so far as to try a "from scratch" re-install of the game, no change.
I have no idea what you mean by a "xbox app" as I don't run ANY "app" and never have - and Minecraft never needed it before 2 days ago when it suddenly for no reason STOPPED WORKING.
Minecraft Launcher is ALWAYS how I have logged into the game.
It is NOT a connectivity issue - I can SEE the servers in multiplayer, I just keep getting "session expired" when I try to log into any of them.
Also, the "Play/Play Offline" button keeps cycling between the 2 states, on about a 1-3 second cycle (it varies a little).
It looks like you have had a widespread error that lost A LOT of the data about who owns Minecraft legitimately, as all of the Minecraft Server COUNTS are down across the board by a lot. especially incuding Hypixel which seems to have lost about 60-70% of it's USUAL user count.
P.S. When I did the "from scratch" reinstall, I got the reinstall loader FROM the specific Minecraft.net site you mentioned.
And no, I do NOT run Windows 10, have never even considered 11 given how many issues I had with 10 in the few months I made the mistake of installing it on my gaming system (and had to REINSTALL it from scratch *3 times*. after every "automatic update" as it insisted on downloading a BROKEN driver for my video card that would not let the machine boot outside of safe mode).