Physics issue in stand alone Quest build ONLY when not connected to pc

So we have a game in progress and in that game we can pickup items and place down. nothing fancy going on BUT problem is. When we build and run in the Quest set we get a small movement when an item is placed down - like the physics readjusts just as we place it, this makes it super hard to stack things.

Now I have discovered that if I run the same build (stand alone not via link) BUT connect the set via USB to the pc while Unity is open (not running anything just open) the issue is completely gone - every time.

Very confusing problem and I wonder if anyone might know what this may be? thanks

edit: also if I run via link the problem is not there

Maybe your code is framerate dependant?
And then you might run 90 or 120 hz on the PC and 72hz on the quest