Palette Swap
Member
Enough people have had that problem (including myself) that I think it might be bugged.
It turned out I was missing a chicken tunnel too, so yeah, I got 100% completion in that zone.I also found nothing when I broke that block, but was still able to get 100%. I think the last few % for me was an overlooked chicken tunnel underground.
That said, there is obviously a glitch, which is the respawning blue block itself. Not sure about missing chests though.
Onward to my completion run then. I reckon I'm in the orb zone in Tule Tree (no map) and it's pretty demanding. I love it, in a masochistic way.