Server animations stop playing when riding/being ridden after unfocusing the game

Partner Rank:

2

Partner Team Reporting:

Everbloom Studios

Verification builds:

1.16.0.63, 1.16.20.50

Summary:

Server animations on entities stop playing when that entity is riding/being ridden after unfocusing the game (showing the desktop in Windows 10, switching apps on mobile).

Impact:

Makes mechanics for an upcoming map that relies heavily on riding entities unreliable.

Also breaks Be a Dragon, as entering a changing room is technically riding an entity. Nearly the entire map is run via animations and animation controllers on the player so unfocusing the game and re-focusing it will make the entire map unplayable until relogging.

Repro Steps:

In Be a Dragon (live):

1. Open a fresh copy of Be a Dragon.
2. Unfocus the game and re-focus it (the Minecraft logo in a white loading screen needs to appear)
3. Try to enter the changing room

Expected: You get teleported to the changing room
Observed: You get lodged inside the door

In provided world (which isolates the issue):

1. Open the provided world.
2. Watch the sidebar, there should be a timer for both the pig and the player (you), which ticks up every second, controlled by an animation on the pig and player.
3. Unfocus the game and re-focus it (the Minecraft logo in a white loading screen needs to appear)
4. Mount the pig

Expected: The timer continues to tick up
Observed: The timer stops completely until you relog.

Screenshots/Videos attached: Yes/No

Yes

Regression Builds:

1.16.0.61

Notes:

Video on YouTube