New customer can't buy my plugin

I’ve just finally published my first plugin, and I’ve had reports that at least one person has purchased successfully. But another is getting to the Checkout page on the Exchange web site and it’s not working.

The section immediately above the Cancel/Complete Order buttons that should say “This purchase is from our online retailer FastSpring” and includes the terms of service checkbox is missing. Instead they are getting an alert at the top of the screen saying “You must accept the terms and conditions to continue”.

Has anyone seen this before? Is there a fix/workround?

Thanks, Martin

I had an update from my customer. The acceptance check-box does not appear in Chrome, but it was fine in Edge, both on Windows 11.