Problem with HW transcoding when HDR tone mapping is on

Plex Media Server
1

Server Version#: 1.41.2.9134 (x64)
Player Version#: Any - desktop browser, Nvidia Shield, LG smart TV
GPU: RTX 4060Ti, driver v 565.90

Transcoding works as expected when HDR tone mapping is disabled. Enabling tone mapping causes transcoder to use CPU instead of GPU.

2

And just noticed - this only happens when transcoding AV1 content. With HEVC everything works fine.
When transcoding AV1 HDR to SDR status page also says (hw) for the transcoding but CPU usage jumps and resulting stream freezes a lot at playback.