Water not freezing into Ice

I'm in a Taiga biome at y level 63 where there is an ice pond that was generated in the world prior to the latest patch. I used to be able to farm Ice from this location, but now the water isn't refreezing into ice. I waited in the area for 2 whole game days to see if it was just slower than normal, but it's still water.

I tested this by breaking a hole in the middle so that it's surrounded by ice on all sides. Also by putting a block of ice next to the shore line to see if it would spread. No luck on either.