Trivial to be sure, but I just noticed there was a message at the top of the Bills Due Reminder (and one for Invoices as well) that indicates "The following X vendor/customer documents are due:" I just processed a payment for 2 bills, and now there are only 2 still listed, but the message still shows a count of '4' documents due. I haven't tested customer invoices yet, but I'll report back if that refreshes as it should or has the same problem.
Not a big deal, just confirming this bug is still present in 3.906 on MacOS 10.15.5.