Context: I have 2 google accounts on Play store, one whose location is set to my home country and the other one I use to download apps which are available in the US only. My home country account is my primary one which has my cards and payment details.
Problem: Unknowingly I downloaded the Sync for Lemmy app with my US google account, and when I went to pay for Sync pro, Google pay showed me options to pay from my US account. I uninstalled the app, went to play store and switched to primary account and installed Lemmy again. However everytime I try to pay for Sync pro, it still shows me options from my other account. No matter what I do, I'm unable to pay for this from my primary account. I've tried to uninstall-reinstall multiple times. I've deleted the app from the play store's manage apps section and reinstall using my primary account and it still doesnt show me my primary google pay options. It is not the case that the app is unavailable in my home region play store.
I hate google pay.
I'd bet it would. Apps seem to randomly decide they want to be associated with the wrong account (particularly their Google Pay association), so I'd bet re-associating it to the correct account using the browser trick would fix in-app purchase associations as well. But I've not tried it for IAP, so I can't say with any certainty that it would work.