I had a similar scenarios in US last March (physical shop, with POS connected). I did not have internet access on my phone at that exact time when I was shopping, grabbed a coffee and pastry at a coffee shop within a mall, tapped my card, POS screen showing “Approved”, cashier handed me the receipt, I drank my coffee and eat my pastry at a tall /standing table and left. When I got to back to the hotel, now on WiFi, the Card App popped up a notification that my transaction was denied. Checked within the app and surely enough it was showing as denied. I was expecting a second attempt at the charge, but it never came through, but still not sure why it would obviously show as Approved on the POS, triggering the transaction completion and receipt printing, to then be denied and the seller not getting the money. I used the same card at other shops within the same mall and these went through, so very bizarre.