I was playing in a singleplayer world and somehow managed to get the "Connection lost: Timed out" screen to show.
When I clicked back to server list it actually took me to the multiplayer menu, which is strange but I think that's a separate bug.
I have no idea what caused this or why so I can't put reproduction steps but I think it's a weird snapshot-related bug.
Can you please provide the game logs from when this happened? Also, is there maybe a corresponding server crash report in your
.minecraftfolder?This is MC-45602.