I have experienced and seen this often. "It", as we said in the old days, "is not a bug, it's an undocumented feature of the system."
I still get a lot of 502's out of CC, it clears on a page reload. I think this is just traffic with RLC, and if cache is clean, it's a delayed response from RLC's Commodore 64 servers... ;D
Now you are telling your age squirrel with the Commodore 64 reference.
;)