There's an issue with filling expiry date at Dustin Home's payment provider's site. When you choose credit/debit card as payment option and proceed you get redirected to https://secure.incab.se/verify/bin/dustinh/index where you'll be greeted with the following view:
Autofill with 1PasswordX and it looks like this:
Autofill with the old 1Password add-on and it manages to fill in the month at least:
Browsers tested Firefox 80.0 (64-bit) and Chromium 84.0.4147.125 (Developer version) (64-bit).
In 1Password I've got the the expiry date entered as MM/YYYY. The site in question only asks for two digits for the year, but this has not been an issue with other sites that also only asks for two digits for the year. I tried changing how it's entered in 1Password for testing purposes but it automatically adds the two first digits anyway when I click on save.
1Password Version: 7.6.781
Extension Version: 1Password X 1.21.0, 1Password extension 18.104.22.168
OS Version: Windows 10 1909 (18363.959)
Sync Type: 1Password