One way to check your system settings is to go into your PS5 settings and check the “color format” section.
To do so, navigate to Settings > Screen and Video > Video Output Information > Color Format.
Your PS5 will read “When displaying 4K HDR content at 60 Hz, the color format will be YUV422 or YUV420 instead of RGB due to HDMI 2.0 transfer speed limitations." YUV422 is HDR for tvs using an HDMI 2.0 cable. It will read RGB (HDR) if your setup is running an HDMI wide bandwidth that supports 2.1.