I have unsuccessfully tried to enter credit card entry on Apple official site - "apple.com".
It seemingly worked correctly just as usual, no problem, but after my 16 credit digit number was autopopulated the site kept saying smth like "invalid number". It basically prevented me from successfully making an purchase on Apple's site.
After multiple attempts I decided to disable the extension and it worked! I was able to pay successfully.
I am posting this as a heads-up to let other users know about this potential issue and solution.
Chrome: Version 77.0.3865.90 (Official Build) (64-bit)
1Password Version: Not Provided
Extension Version: 1Password X 1.16.2
OS Version: Mac OS: 10.14.6 (18G95)
Sync Type: Not Provided