Inv Full Msg on Drops When Inv is Clearly Not Full

I'm getting system messages after kills saying "You cannot obtain any more because you inventory is full.", but I'm clearly not full. I just had this happen, and my main Inventory currently has 79/100 and there is nothing showing up in my drop storage, which is currently empty. Are there caps on the number of items you can have in a stack? I've reviewed every non-weapon/item (food, augments, etc) and none of the stacks appear to be at a cap, a few like Photon Quartz are over 100 and there doesn't seem to be an issue there. Is receiving this inv full system message a known issue? I'm worried I'm losing some kind of drop when I shouldn't be.

e09cbe1a-23e0-4acc-a147-995498de081f-Inv Full Msg.png

19d1aa79-7dbc-4ae8-afa1-1729ccc36002-Current Inv.png

You might be trying to pick up an item that is at max stack size, I get that every so often when attempting to restock a healing item yet a lag spike didn't register me using one before hand.

To combat some storage issues I recommend buying the material storage

The might be a glitch cannot confirm or not because this is just hypothetical If by any chance you have a secondary character with items it may be overlapping them in the integer checker of how many items you have