Unable to join or invite friends to group.

[Winter]

Seems to be only affecting me.

In the menu, friends in discord, I click on Invite on bottom right corner.

USUALLY the steam overlay appears and I invite friends, but this doesn't happen anymore.
Instead I get a

Please Wait
Joining Group...

and I'm stuck on that screen, music still playing, but I can't escape, back out, or click anything. It stays like that for hours, literally.

Friend tries to invite me instead, I click accept, nothing happens.
Click accept through steam, nothing happens.
Click join game through steam

Please Wait
Joining Group...

Progress I thought, nope. Same deal.

Alt+F4 is the only way to get out of that screen.

I've verified files, I've reinstalled the game, I've even looked online, perhaps not deep enough, but enough that it isn't on the 2nd page of Google search results.

I can join a random matchmaking game just fine, but I can't join or start a group in the lobby while my friends are able to just fine. Why just my game? Worked just fine THIS MORNING. Nothing changed since then.

Does anyone know a fix? Maybe have had this issue before?

[Winter]

Annnnnnnnnnnnnnnnnnnnnnnnnd of course once I dig a little bit deeper I found the solution.

https://support.gearboxsoftware.com/hc/en-us/articles/205281420?input_string=unable+to+join+or+invite