I notice when you log connect to Patreon using Itch that Itch says there is a minimum dollar amount to gain access. Patreon recently localized currencies based on the users and this broke a lot of things for people using dollar amount instead of tier names to determine whether someone gets a reward or not. This may or may not be related but I figured I’d toss it in as a possible reason for the errors.
The currency thing was massively irritating for sure, but I found it doesn't differentiate between currency values, just the number itself so I lowered the amount to the lowest type of currency (if that makes sense) and that fixed that issue. It worked perfectly fine last month when that was introduced, but this is something that's coming up only in the last couple of days.