Fox crouching animation affects other nearby foxes
I summon 4 NoAI foxes in Sitting, Sleeping, Crouching, and normal state.
When the fox with Crouching:1b NBT tag is in the scene or rendered, it will affect all the other foxes animation.
Although those foxes' NBT tags are Crouching:0b, they all sway their bodies, just like the one with Crouching:1b NBT tag.
In the background, there're 4 NoAI foxes, and those 3 in foreground are alive. All of them will shake their body.
Created Issue:
Fox's weird animation
I summon 4 NoAI foxes in Sitting, Sleeping, Crouching, and normal state.
When the fox with Crouching:1b NBT tag is in the scene or rendered, it will affect all the other foxes animation.
Although those foxes' NBT tags are Crouching:0b, they all sway their bodies, just like the one with Crouching:1b NBT tag.
In the background, there're 4 NoAI foxes, and those 3 in foreground are alive. All of them will shake their body.
I summon 4 NoAI foxes in Sitting, Sleeping, Crouching, and normal state.
When the fox with Crouching:1b NBT tag is in the scene or rendered, it will affect all the other foxes animation.
Although those foxes' NBT tags are Crouching:0b, they all sway their bodies, just like the one with Crouching:1b NBT tag.
In the background, there're 4 NoAI foxes, and those 3 in foreground are alive. All of them will shake their body.
I summon 4 NoAI foxes in Sitting, Sleeping, Crouching, and normal state.
When the fox with Crouching:1b NBT tag is in the scene or rendered, it will affect all the other foxes animation.
Although those foxes' NBT tags are Crouching:0b, they all sway their bodies, just like the one with Crouching:1b NBT tag.
In the background, there're 4 NoAI foxes, and those 3 in foreground are alive. All of them will shake their body.
I summon 4 NoAI foxes in Sitting, Sleeping, Crouching, and normal state.
When the fox with Crouching:1b NBT tag is in the scene or rendered, it will affect all the other foxes animation.
Although those foxes' NBT tags are Crouching:0b, they all sway their bodies, just like the one with Crouching:1b NBT tag.
In the background, there're 4 NoAI foxes, and those 3 in foreground are alive. All of them will shake their body.
Related to MC-145142

Please check if that's still an issue for you in the latest 1.15.2 stable release.
This is 100% still an issue as of 1.16.1
Occurs in 1.16.4
Occurs in 21w03a
The fox crouching animation only occurs on other foxes is the crouching fox is visible on-screen.
Occurs in 21w05b
Occurs in 1.16.5
Affects 1.21 Pre-Release 3. I'd like to request ownership of this report, as the original owner has been inactive for 5 years, and I would like to add the necessary commands to reproduce this issue to the description.
2024-06-06_18-12-37.mp4