I’ve been playing on “console” (SteamDeck) so I know the UI is different but the issue I’ve found is that there are three different “inventory” options and two different “loot” options, and each behaves a little differently.
For example if I loot a corpse, you’re right I can send to a specific party member. However if I loot a chest, that has to go to me.
Similarly when I the character sheet inventory view I can sort by certain methods and then L3(?) to exit that menu. If I’m selling something it’s still (L3?) to open that menu, but B to exit it. Also the sorting options aren’t the same. Also switching between characters during a trade event is one button. However switching on the character sheet is three buttons. There is also a third lesser used “put in device” menu with even fewer sorting options and you can’t switch characters.
The game is excellent and you can get used to these things but I do sometimes have to spend time just sorting things.