So I created a player pawn from scratch within the top down blueprint project in 4.27.2 (Fresh install).
I based the pawn’s camera logic largely on the one that was in the default project but added the ability to change the camera position with the mouse. When I initially started testing, everything seemed to look and work great. But then I panned the camera down and saw that the pawn was off of the ground.
I tried lowering the player start and noticed that when I started the game the camera was under ground. I checked for all kinds of collision and clipping logic but that didn’t seem to be the culprit so I then moved the player start back and just moved the mesh within the pawn down. The root is a collision box so it was no issue to move the mesh.
The end result was the same, but this time I hit eject and noticed that the camera and boom arm just moved to a new location within the pawn mesh. I honestly cannot figure this out but it is not a complex blueprint or pawn so I am at a loss as there is little more that I can think to check.
I will include a couple pictures for reference but can add whatever additional info is required to anyone that can assist.