When you switch from pistol in hands that was first stored in a holster to another item using hot bar, the pistol doesn't end up back in the holster. It winds up in a random place in your inventory. That means that if you are full and switched to an item from your backpack (like your main weapon that most smart people store in their backpack), pistol often ends up where that item came from and now you can't clear your hands without shuffling pistol to where it should be in holster or dropping item on the ground. If you double click in your inventory on the pistol in your hands or hit its hot bar button, it will go back to the holster it came from like it is supposed to. Knives stored in holsters and boots have the same issue as do canteens on your belt. Bug with where items go back to appears to only happen when you switch to an item using hot bar.