Gigapixel AI 8.0.1 won't update, nor uninstall

Opening 8.0.1 it tells me there’s an update available. I click on it and it tells me what the changes are in 8.0.2, and asks me to update, which I do. Then the top right window invites me to install update, which I do. Windows tells me it’s not an approved windows store product, and I override the setting to install anyway. Installation commences, and then quits, telling me I already have an account, or just drops out.
I thought I’d try uninstalling 8.0.1 via windows apps & features. It starts to uninstall, but then quits, also telling me I already have an account. Windows apps & features tells me I have installed 8.0.2, but that’s probably because it started to install it. When I open gigapixel, it tells me it’s still 8.0.1, and invites me to update it.
I downloaded the installer 8.0.2 from my topaz account, and hoped it would just overwrite the existing installation. It doesn’t. Again I already have an account.
I am unable to complete this upgrade. I am running windows 10. Any body know how to do the upgrade?