I have the EXACT same problem with mine. I was organising my inventory and suddenly my charm count is glitched. I have 35 in my inventory yet the count that is on GoFusion is stuck at 20 snowflake charms and I can't craft anything. When I go to make a trade two seperate stacks of snowflakes appear in my game inventory, one 20 and one 35. :/
I don't know what to do besides collect charms on my mule.