USPS Shipping Module Error - will not allow priority on step 2

Hello,

After years of it working fine, the USPS module suddenly decided to stop allowing "Priority" as an option, although when you're on step 1, you can pick between "Priority" and "Express". However, regardless of which you pick, in step 2, it only shows "Express" as your option.

We also have a "Best way" option and that still works fine if you pick that in step 1 and continue to step 2.

Anyone have this issue? I don't even really know where to begin in terms of troubleshooting....would it be an issue with the USPS server or some weird Zen Cart code quirk?

Thank you,

Mike