Date & Time: April 14, 2021
Frequency: Always
World name: Coeurl
Character name: Sefi Ar'lya
Retainer name: N/A
NPC name: N/A
Monster name: N/A
Class/Level: 80
Party or solo: N/A
In-game time: N/A
Area and coordinates: N/A
Housing: N/A

Steps:
Incorrect Behavior:
1. Update PS5 to latest system software released on 21/04/14: 21.01-03.00.00.38-00.00.00.0.1
2. Go to Settings -> Screen and Video -> HDR, set to "On When Supported"
3. Launch FFXIV PS5 client
4. Observe/Confirm via television is incorrectly receiving an HDR signal (in my case HDR10) from the PS5.

Compare to the PS4 client running in backwards compatibility mode on PS5:
1. Update PS5 to latest system software released on 21/04/14: 21.01-03.00.00.38-00.00.00.0.1
2. Go to Settings -> Screen and Video -> HDR, set to "On When Supported"
3a. Launch FFXIV PS4 client using backwards compatibility
4a. Observe/Confirm via television is correctly receiving an SDR signal

Model number of the Playstation 5:
■ CFI-1015A

Using PS4 backward compatibility: No

Information About the Peripherals You Are Using
-Type: TV
-Maker: Sony
-Model Number: XBR-55A8H