That'd be my guess is the snow is bridging over the holes high enough off of the water so the water cannot touch it to melt it. I'd be willing to bet that the larger hole proves that theory.

Can you guesstimate the sizes of the holes in the ice in the first picture? (11-25-2019)
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).