In an HDR project in FCP the text shows up as grey.

From: Adjust titles in Final Cut Pro for Mac - Apple Support

"If the title is in an HDR project, optionally change the title’s HDR intensity by clicking the Title button at the top of the inspector, then dragging the Graphics HDR Level slider."

What you are seeing - correcting the title affects the layers below - depends on which title you use.

Some titles are made like that (with a "title background" layer), some not.

For those that behave this way, you can prevent it by enclosing the title in a compound clip, effectively separating the title from whatever lies below in the timeline.

I pointed you to the official FCP documentation but I didn't understand from your original post that you are using a 3rd party titles so the documentation wouldn't necessarily apply.

As Luis suggested, for 3rd party titles that don't explicitly support HDR, try wrapping them in a compound clip and applying the correction there. As LocaAlicia implied, try contacting their support to request their titles support HDR.

So all those packs I bought for animated text are no usable!

The default titles work fine. If you're using a personally purchased title, that's the manufacturer's responsibility. There's no point in complaining to Apple.

BenB wrote:

"You can increase the color intensity of title elements to HDR levels by adjusting the Graphics HDR Level slider."

I've been through most of Apple's supplies stock title templates, and NONE show any HDR levels slider, so this is bad information on Apple's part.

I've tested many of Apple's and third party title templates on HDR projects, and can't reproduce this issue.

The titles, as seen in Motion, do have a "HDR White Level" slider, which is Published (and that means, of course, that it should appear in FCP). For some reason, though, it is not (or no longer) being honored in FCP.

"You can increase the color intensity of title elements to HDR levels by adjusting the Graphics HDR Level slider."

I've been through most of Apple's supplies stock title templates, and NONE show any HDR levels slider, so this is bad information on Apple's part.

I've tested many of Apple's and third party title templates on HDR projects, and can't reproduce this issue.

I submitted feedback via Feedback - Final Cut Pro - Apple

We don't shoot or deliver HDR so I haven't used it, but this is the first time I can recall where the docs do not reflect the app correctly. I always point people to the official docs because in my experience they've always been the source of truth. This HDR Levels slider description appeared in the docs for FCP 10.6.6. Perhaps the slider was exposed then but some future FCP update broke it.

Motion:

FCP: