Traveling & Breastmilk not freezing

I'm currently traveling and the hotel is storing my breastmilk in a back freezer (no freezer in the mini fridge). I have a soft cooler like a lunchbox and several ice packs. All the ice packs thawed after my flight and work day. After my first express I had the whole bag with thawed ice packs and fist batch of milk placed in the freezer. This morning I added 3 bags and discovered the ice packs were frozen solid but non of the milk froze overnight!?! Has anyone had this happen? I'm so confused. I had the milk layered with packs between them.... The hotel staff were confused as well and let me check the freezer, it's cold and nothing else was thawed... I currently have milk outside the travel bag laying flat. I'll check on it when I get out of work.