Luckily, we all know already that I am a dildobrain, so this should come as no surprise to anyone: I coded the subscriptions wrong on the Donate Via Subscription page during the last update, so they were set to be annual donations instead of monthly. So, if you signed up to donate $20 monthly, you are instead donating $20 annually.
The buttons are working correctly now.
If you subscribed via the dropdown in the sidebar, you're fine. But if you subscribed via the Donate Via Subscription page, you may have to cancel your subscription and resubscribe because of my mistake, if you do indeed want to be donating monthly.
I am desperately sorry for the inconvenience.
My profound thanks to Shaker ChocoholicBec who noticed my error and took the time to tell me. Thank you so much.