I offer my Android app at several stores: Google Play, Amazon Appstore, Huawei AppGallery
For all of them I use the same signature and package name. The akps differ only in the purchase verification. The version for Google Play checks at app startup if it was purchased from Google, accordingly it is the same for Amazon and Huawei.
I uploaded a new version to all three stores two weeks ago. Huawei released the update after just one day.
And something very unpleasant happened: The AppGallery updated all apps, not only those that were originally purchased from the AppGallery.
As a result, customers who have a Huawei smartphone and thus the AppGallery, but originally purchased the app from Google Play, could no longer launch the app. The app checked if it was purchased from Huawei, which it was not. The user was shown an error, to please buy the app now or change the account.
Accordingly, I received a flood of mails, calls and bad reviews. Google Play customers were now able to leave reviews in the AppGallery, although they had not bought the app there at all...
Am I wrong, but shouldn't every app store only update their own apps, especially purchased apps?
I have been offering my app for years at various app stores, same signature, same package name (previously also at AndroidPIT and Samsung Galaxy Apps), this problem has never occurred.
You should use a different keystore for each market, this way the app can only be updated from its original store.