I tried all of those settings and while using my ATV unit, the Dolby Vision signal wouldn't activate on my LG OLED. No problem seeing the Dolby Vision signal come on my OLED using the Roku Ultra unit.
Are you sure HDR is activated on your display. What model is your display?
My PJ, Epson 5050UB, doesn't support DV, so I'm only seeing HDR10. Not sure how DV gets handled in that case (though one would've thought the same).
Unfortunately, I don't have any DV capable display to try/test DV output for this.
_Man_