Plugging phone into laptop charges laptop instead of phone

When I plug my father's Xiaomi 5X into my MacBook Pro, it shows up as a charger on the MacBook and I don't get the usual USB options on the phone. Tried it on two Macs with same result. Also tried my Pixel 2 with the same cable and that worked as expected. Is there some setting in either the phone or laptop that I can change to make it recognise the phone for what it is?