Regolith sometimes pops out of the sample dock for no reason (OW-1039)

[AstroStucky]

Adapted from Jira OCEANWATER-1039 originally reported by @AstroStucky

What happens

After a delivery of regolith into the sample dock, regolith may randomly fly out of the sample dock. This appears to be a physics issue. It may also occur with regolith just sitting in the scoop and the arm not moving, but this appears to be far less frequent.
 

What should happen

Regolith at rest should remain at rest. This is clearly a non-physical issue happening with the physics engine.