The spot where I noticed it...

and that save, with me standing at exactly that position, so "grab" should pick up the inserters, but not any circuits.
Save file
This is the most minor of minor bugs, likely the fix will be proportionally easy though.
Just ran around my base trying other corners, wasn't exhaustive but tried at least 4 of the 8 possible corner belt configurations and seems to be happening on all of them.