Player's cape rhythmically spasms when riding certain entity stacks

Relates to MC-270701

The bug

In the configuration provided in this ticket, the player's cape will move strangely when riding a configuration of entities.

How to reproduce:

1. Summon a chicken riding an experience orb:

   /summon experience_orb ~ ~5 ~5 {Passengers:[{id:chicken}]}

   , being careful not to pick up the orb

2. Ride the chicken using the /ride command:

   /ride @s mount [UUID of chicken]

3. Switch into third person

Expected results

The player's cape would remain in a roughly stationary position.

Actual results

Every second or two, the cape slaps the player's back. This appears to be mostly in sync with the experience orb issue mentioned in MC-270701, indicating they are related somehow.