It's baaAAaack... or a variation of it.
My barracks is upgrading so adventuring is on pause and changes in pop count are pretty obvious, it's been steady at 89 Working and 0 Unemployed for a few days now but this morning there were 84 workers and 5 Unemployed without 5 collapsed buildings to explain them. It reset to the correct "0" at some point and an earlier collection spawn didn't affect it. Then a new set appeared, collected one and:
[collect]
[collect collect collect...]
I can't account for the earlier "5", either I completely overlooked them... somewhere (there has been no "collect 5") or it may be cross-pollination with this or this or... something, but this last round was clearly collectibles.
Changing zones (visiting another island) and refreshing haven't fixed it though it may, like earlier, reset itself at some point.
Edit: 'nother round of collectibles but no bug in this one. The numbers are still wrong, too few workers and too many unemployed, but they're not wronger. Puzzling.
Edit II: In the pre-Maint mini spasm the other day it reset to 0 Unemployed and 89 workers. This morning, 27.08, it's gone buggy again and collecting a collectible transfers an active working Worker to the Unemployed queue.