Unable to pay Adobe Acrobat Pro subscription online

I've been trying several times a day over three days to change my card number to submit my monthly subscription payment for Adobe Acrobat Pro using the Chrome browser (Version 71.0.3578.98) on my Windows 10 (with release 1809) desktop PC. The error message is something like 'an error occurred, please try again or use a different browser.' I've had no trouble changing to and using this new card at other websites.

Does anyone know why this is happening and what to do about notifying Adobe?