Putting pets in seat not functioning correctly

[Master-lego]

Describe the bug

Putting "pets" (nearby mobs) in a vehicle seat is not working properly.
To Reproduce
Steps to reproduce the behaviour:

1. Spawn a vehicle e.g. Twoseater Biplane.
2. Spawn a mob.
3. Leash the mob
4. Right click with lead item in hand on passenger seat.

Expected behaviour

When right clicking passenger seat with lead while a mob is leashed, mob should be placed in passenger seat.
Screenshots

Versions (please complete the following information):

• Forge: 14.23.5.2768
• Flan's Mod: 5.6 beta4 (any version since 1.12.2 release)

Additional context