The title/subtitle generated by the /title command that was generated while on a multiplayer server is now appearing permanently on the screen of a newly generated singleplayer world, as seen in this screenshot:

The title remains on the screen even if you leave the world and return, and is also persists when you enter previously generated Minecraft worlds. Returning to the multiplayer server that generated the title (in this case, Hypixel) removes the bugged title, and it does not return when rejoining the singleplayer worlds. The bug also occurs if you disconnect from the multiplayer server and join an existing singleplayer world. The particular title causing this bug remains on the screen constantly while in the server's AFK lobby, and the bug does not seem to occur with titles that fade in/out of the screen. This issue can be recreated even in a new session of the game.{}

Steps to Reproduce:
1. Enter the multiplayer server
2. Remain AFK until transported to the AFK lobby and the title appears on screen
3. Without moving in-game, disconnect from the server
4. Enter a singleplayer world, the title should remain on the screen