At the one (Irish-y) burger joint in the first floor of a historic hotel where I work now, the POS (point-of-service) system on the tablets that we carry around with us is a real POS (piece of shit).
You have no idea how hard it is to move items from one check to another if they’re put on the wrong table or put on the wrong check when there’s a split check at the table…
Once when a lady was unhappy with her cocktail and we went to delete it, I handed my tablet to a manager for her to punch in her code and take it off the bill, only, one of the beers further down off-screen must have been previously tapped and accidentally highlighted, too, so that also disappeared, and it was only because the customer noticed it at the end of the meal when they were looking at the receipt that we were able to go back and add it back onto the bill where it belonged.
It really makes you wonder what’s going on with software design, where a product isn’t easily usable on such a basic level with such a basic everyday task in the workplace.