VP9 should play normally. Please point me to a sample that exhibits the problem.
https://kodi.wiki/view/Samples
VP9 Profile 2 HDR 24.000fps The Redwoods (in MKV) (thanks @wesk05)
https://mega.nz/#!pQEGgRwY!pD9whIlM-U9tJIA-LojxSt582BAZGfdSA5wAQLT06I4
VP9 Profile 2 HDR 59.940fps The World in HDR (in MKV) (thanks @wesk05)
https://mega.nz/#!hJdFEIBI!uSOjZtkkjIVYSfqD9aSfONf1yq__uQvlsf47pCtFvdQ
For both: Can't play video message
FW 2.2.96