I have the same issue. Just bought an iPhone 8 from the apple store (model a1863) but getting an ineligible to swap error when trying to activate it.
Hi there, @boostmobilefan! Thank you for stopping by. We're sorry to hear that you're in this type of situation. Did the phone pass our online eligibility (https://activate.boostmobile.com/bring-your-phone?intnav=TopNavhones:BringYourPhone)?
Hello! We're sorry about the issues you're having. We'd love to assist you. Can you send us a private message with your phone number, pin code, and complete address to review this?