Final Cut ProX HDR

Recently upgraded to:

1Phone 13Pro iOS Version 16.11

MacBook Pro 13. Mac OS Ventura 13.0.1

Final Cut Pro 10.6.5

I've recorded video 1080 HD @ 30 FPS with HDR "on" using the iPhone.

In FCP, media clips play in the viewer as expected, however when a clip is placed on the time line the picture appears way over exposed in the viewer.

In "View" settings selected:

QUALITY (Better Performance)

MEDIA PLAYBACK (Optimized/Original)

DISPLAY (Show HDR as Tone Mapped)

In FCP Preferences however, the "Show HDR as Tone Mapped" check box is unavailable.

As I understand it, "HDR as Tone Mapped" should be on to view the HDR picture in the viewer.

I would appreciate advice on what I might be doing wrong.