Version Info

• Minecraft, 1.20.1-Forge
• Moving Elevators, 1.4.9

Are you using OptiFine?: No, I use Embeddium and Oculus.

Description of the Bug
The problem of falling down from the elevator if I sit on the chair inside the elevator and try to go up or down

Steps to Reproduce

• Download the sit-1.20.1-1.3.5 or create-1.20.1-0.5.1.f mod.
• Place stairs or "create mod" seats on the sides of the elevator.
• Sit down and try to go up or down.

Screenshots

Those mods likely dismount you from their entity whenever the corresponding block gets removed. They likely dismount you below the floor height of your platform, hence you fall through.
Not sure if there's anything I can do about that.