While covering a 128x128 area with snow using snow golems, after about 16 hours of the snow golems doing their thing, they started taking damage and dying spontaneously. The weather was clear. Most were in an ocean biome, but several were off in a naturally snowy biome. Bringing other golems into render/sim distance also caused them to immediately take damage and die as well as creating new golems. After awhile, the issue resolved itself and I was able to create more golems.

Awhile later, an enderman spawned on the snow. Once I slept and made it day, the enderman started taking damage and teleporting until it died.

It almost seems like the snow was acting like water sometimes, which might explain these 2 occurrences?