The boxes around the items look a bit deeper red than the ones I’m using which look a paler red/orange, unless its just the background vs mine making them look different it could indicate something
I assume your settings aren’t really an issue, since the model should be showing anyway,
There could be a limit to the device, after which they start to fail.
I have a map with about a hundred of them, maybe more and that was OK.
For the placers I’ve only used Model, but yours are set to icon, maybe the 2D can’t be as close to a wall, even though you can see the back of the icons red box, have you tried moving them forward a bit ?
The model your using for the wall see if changing the collision mesh complexity setting helps, because of the shape it could have a different collision mesh which is engulfing the item placers positions.