HDR10 spec for Panasonic Viera TH-65AX800Z

Hi y'all

So I've got my Oppo 203 4K player connected to my Yamaha RX 3060 receiver. TV is connected to receiver using its 4K/ARC terminal. I've set HDR output on the player to on. When a 4K disc plays, the OSD on the TV HDR 10 briefly appears.

So........is the TV outputting HDR 10, or is it just indicating that the player is sending a HDR 10 stream??

Spoke to tech support at Panasonic, he was unable to help.

Cheers