Google weather app home shortcut won't delete previous locations

[jpjof]

I use the Google weather app on my home screen. It has 7 previous locations I've saved but I can't delete any of them. If I long press on a location in the list it disappears, "location removed - undo" appears, and then the location itself immediately reappears. I can't add any new locations while these are still there. It's infuriating! It used work fine.
Grateful for any help.
Moto G5+
Android 8.1