Can't update files on my iPhone but can download, it is a problem with region, how to fix it?

IPhone 6 doesn't update apps telling me 'Account Not In This Store, your account is not valid for use in the UK store. You must switch to the Egyptian store before purchasing.' Although I'm on the Egyptian store as I see from settings. However when I come to downloading apps it works fine, seems like the problem is only in updating. I tried restarting phone many times and when I come to change the region it says Egypt. So it is the Egyptian store. So, I logged out of iTunes and logged in again and still doesn't update. What's the problem and how can I fix it?

You are linked to the App Store of the country of your billing address (the billing address on your credit card) for your Appld ID account.

Perhaps there's a bug in the update logic of the store. I haven't seen this specific error, however.