1/23/23 I attempted to purchase the Version 2 upgrades of AD & AP (I had purchased the Versions of 1.9.3 a 1yr +7mos prior) but I also had issues using Discover.
I likewise am from the USA & regardless that Discover IS indeed an option, it never went through.
I received multiple messages in a Red Box (*see attached) stating "We're sorry but something went wrong while placing your order. If you continue to see this message, please contact support operatives who will be able to assist you further." (<--Ah, Lol, funny!)
I did contact Customer Support Operatives. A reply took nearly 2 weeks, before finally hearing from an "ANDY". Who was (& I'm being quite polite here) less than 'HELPFUL' especially for a CUSTOMER SUPPORT OPERATIVE!! In short, I informed him that I HAD checked for MBPro UPDATES! Checked for UPDATES on Safari, Chrome, Firefox! Logged Out, Shut Down & Rebooted my MBPro! Knowing there never was any issue with my Discover card or my credit etc. Then confirmed with Discover; the issue was not on my end.
Andy, being oh-so-helpful merely blamed it on my Discover Card, regardless. Then I went on to use that very Discover Card later that day. Again the issue was never my card. I attempted this purchase on multiple days, times & browsers. Finally, I came to realize Serif/Affinity simply does not want to- will not accept Discover. Perhaps they do via a Pay-Pal / Discover transaction purchase, but not directly from Discover, not from where I am in the USA. C'est La Vie!
Oh and Andy... DO BETTER, the Affinity Customers deserve that, I CERTAINLY did!