Playback of 1440p/2160p content with h.264 encoding from the Cobalt test suites (YT2018 spec) fail for us on Broadcom chipset. Are these test cases even supposed to work?
The Cobalt linux-x64x11 cannot play h.264 1440p and 2160p content either, and as far as I know, all YouTube content above HD is encoded with VP9.
Jan Boquist, that is expected and not relevant to the browser(or Cobalt) you use. If you have further questions about this, please reach out to your YouTube technical account manager.