Hello, Mateusz,
We apologize for the delay in our response as we were working with the development team to address your issues.
1. Regarding your first issue, the video you provided is archived and we are unable to view it. https://prnt.sc/XPjEj4YsXLbw
2. We also tried using a VPN in Poland, but the issue still persists. We do not believe that another video would help us, as we would still be unable to resolve the issue without access to it. We suggest that you open up delivery methods for the short-term so that we can make the necessary fixes, or create a staging environment and grant us access to it.
3. Regarding your third issue, the checkout page appears to be working properly: https://prnt.sc/agdF2AYkLj_e
Best Regards,
8Theme’s Team