Maybe so. When I open the settings in Play Store app, "Notification available" is enabled "as soon as updates are available".
When I try to disable it, a system window pops up saying "No notifications are allowed from this app".
Is it better now to enable it in GrapheneOS and disable it in Play Store? Would that be a solution?
Update:
I just found out that in the settings automatic updates were checked. I unchecked it. Hope the issue is fixed with that.