App Page for a commercial Watchface (Garmin Payment) doesn't show any compatible devices

maybe it would help if you included the devices list from the manifest

Good idea, thank you!

It won't be approved with Garmin Payment if you include devices that don't support Garmin Payment, like the Instinct 2.

The list is documented, but might be dated: https://developer.garmin.com/connect-iq/monetization/app-sales/

If there is a new device that's not mentioned, check the devices supported by other apps that use garmin payment.  For example, the vivoactive6

Ok, thank you, sounds good. As a rookie I didn't focus this issue. But:

I uploaded a new version with

I'd give it some time.  Maybe a day.  If I recall, you'll get an email when you are approved with Garmin Payment.

Practical experience:
It doesn't matter if there are watches in the supported devices of a paid app that don't support Garmin Pay. Only the models that are supported are listed on the app page.
The fact that the MIP devices of the Instinct 3 series are now included according to the list is news to me. In any case, they are not listed as supported devices in any of my app listings, even if they are listed in the manifest. 
It would be cool if you could provide an update on whether it actually works with an Instinct 3 Solar, but I wouldn't get my hopes up just yet.