Everything worked but GPay refuses to work:
Your Phone can't make contactless payments
Check your phone software to see if it meets standards
So GPay does not only check the OS - it checks the bootloader, too.Your phone doesn't meet software standards
You can't make contactless payments with this device. It may be rooted or running uncertified software. Contact your device manufacturer or visit Google Pay Help for more info.You can still use Google Pay to pay online.OK
Even if you did not rooting/jailbreaking your OS...