Hi Christoph,
The 1009 and 303 errors that you're running into aren't uncommon. That being said, we only deal with technical queries related to SDK performance and implementation on this forum. For help with this kind of serving issue, you'll have to reach out to AdSense through the CONTACT US link on
this page.
To be thorough, I tested your tag in our
Video Suite Inspector. The tag you linked returns a different VAST response on every request, and I never ran into one that used wrappers. If you continue to see issues, please share a specific VAST response that you're seeing the issue with.
Regards,
Chris Feldman
IMA SDK Team