Sorry for the issue. Are you looking to export your sequence in HDR? Please let me know which camera was used to shoot the footage. I would have a better understanding of your project if you could share a screenshot of your Lumetri Color panel (Window > Lumetri Color, open Settings, and expand all options).
HDR is still the Wild Wild West out there, sadly. And as there's so much more the user needs to control, far more complex than old-style Rec.709 workflows.
So, what do you have set for your graphics white point on that sequence?
p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.