Is USPS Regional Rate Box still Priority Mail or Ground Advantage?

[SFICDan]

USPS Regional Rate boxes are discontinued but can still be used... from the USPS website: "Regional Rate Box prices have been discontinued. Remaining boxes can be used for shipping at weight-and-rate packages."

When I enter a USPS Regional Rate box using Shopify shipping I get many options, including Ground Advantage.  My Post Office would not accept it as Ground Advantage, and insisted it still needed to be Priority Mail.  Is Shopify wrong, or is my Post Office misinformed?

[Mirdas]

Hello @SFICDan , using Ground Advantage with USPS Regional Rate boxes could be confusing. We would recommend that you use Priority Mail with USPS Regional Rate boxes or simply disregard the boxes and opt for Ground Advantage.