I called Chase today and they told me they only support Apple Pay. I've had that working for the last year or so. I just tried adding the Chase card to my Fenix 5 Plus and it's a no-go :( Hopefully this will work soon. I couldn't get my Bank of America card(s) to work either. So far I'm 0 for 3 on adding cards to the Garmin wallet.
It would really be helpful if Garmin Pay cooperated with Paypal, as for example Google Pay supports Paypal (applying a virtual Paypal MasterCard).