Also chiming in,
After updating to the newest version, any customer that had attempted to use paypal method had received an error if they were outside of the country we had set as our default currency. I wasn’t even aware until we received an email from one of our customers. It seems that there is a common trend where currency plugins are having conflicts with the latest update.
“error: expected currency from order api call to be cad, got ___”
Rolling back to the previous version has solved the issue for now. If you are using a currency plugin, please be aware there may be some conflicts with 2.9.1