Try not to use pin, bullet, sine or any other similar behavior with Physics object.
It's an official recommendation from Scirra:
it is highly recommended to control Physics objects entirely via the Physics behavior (by setting forces, impulses, torques etc.), rather than trying to manipulate objects by Set position, Set angle etc.
(...) For example, setting an object's position or angle will cause Construct 2 to teleport the corresponding object in the physics simulation to the object's new position, which does not always properly take in to account collisions. The same is true of using other Construct 2 behaviors at the same time as Physics.
I don't know if it's applicable in your game, but maybe you could disable physics behavior when it's not required, then you can manipulate objects with Sine, Bullet etc. Re-enable physics when it's needed.
If you are only using physics for its gravity, you can try Bullet or Platform with gravity instead.