It seems like it could be how you set up delivery/shipping rules or for whatever reason the Printify location did not set properly (rare). Normally, I would not do this, but I created a POD app for hats, shirts, and hoodies (made and shipped from Arkansas). If you want to try that app, I can help troubleshoot directly.
Otherwise, I would recommend you just uninstall and reinstall printify and ensure the location is correctly set in yrou settings > locations