After updating from 1.19.10 to 1.19.11 me and my 4 friends came across this issue when we tried to play on our SMP world:

"Unable to connect to world"

So we tried a lot, everything from re-installing Minecraft to re-adding each other as friends, and so on.

And now I'm here, reporting this issue, we could play completely fine earlier this day (the same day as update)