PC, X in Inventory, does not let me drop items

Hello.

Playing PC, go into Inventory, and the X does nothing, not allowing me to drop items.

I can use the E to Select, F to Inspect, R to Mark, Tab to close.

This best I can do is sell items, at a machine, but that is inconvenient.

Any suggestions?

Just discovered that you have to press X and hold it down for about 3 seconds, before the item is dropped.