How to reproduce:
Build structure like this, put any entity on the edge of the slab and fly in with creativeNoClip turned on

Can you please post the full mod list (with mod versions)?

The reason of that is the same as the way to detect projectiles in < mc1.16: the boat entity ticking triggers checkEntityCollision or whatever method of the pressure plate, and the pressure plate finds a non-spectator player in range so it triggers

I was perusing the issues and this one seemed simple enough!