On January 1st, we had our first run of charging storage fees. (The only cards that have been subject to the $0.01/month storage fee have been those being flipped.)
If you would like to see which of your cards will be charged the $0.01 storage fee on the 1st day of the next month, you can simply select the “Only show cards subject to storage fees” in the filter dropdown on the Manage Inventory page.
You can always review your Store Credit History to see any recent transaction that affected your store credit. This now includes any storage fees.