When I first started out, some fellow beeks suggested that I put pollen patties on in the fall. Said they will use it in the spring to raise brood. Sounded like a good idea at the time.
When the later part of January rolled around, we had a couple of warm days. The front of those hives were covered with spotting like yours. None of them made it to the spring. I learned my lesson with feeding them solids when they have to hold it very long.
I'm not saying that was your problem, just my experience with fall feeding pollen patties.
I still have one every couple of winters that get this condition. I guess it's just a bee thing. :bee: