HEVC Only Encoding As 8 Bit

Working with Sony Alpha 1 8K 4:2:0 10 bit HDR files. All files show as 10 bit in the media browser. But when I export H.265 for upload to Vimeo, the resulting .mp4 is only 8 bit so Vimeo will not recognize it as HDR 8K footage. Obviously missing something here so appreciate a push in the right direction.

Are you using the Main10 profile in the delivery page?

Are you using the Studio version of Resolve?

Definitely using Studio. I'll double-check whether Main10 profile.

Thanks