.... tippy toeing in .... the program Hexagon is a tad touchy, k.
Sometimes we can spend hours perfecting our masterpieces and then, oh maybe hit one too many or misplaced, who knows, “Edit > undo” ... and all the shading domains go “poof”.
They would need to be redone in Hexagon. Save Project. Click on page to be sure it’s saved [no little * after the name], then export out the treasure.
All the shading domains “must have” their “own names” and their “own” colours/textures. There’s a little goofy in communication between these 2 programs and if perchance all the shading domains had for example, the default shading material assigned to them; well, they’d all be given the very same shading domain/mat zone in D/S.
Edit: okay I’m seeing another post there now that you do have the zones showing, just with them all with the same texture assignment.
Still, might want to check back in Hexagon to be sure that they all had their “own” colour before export. Oh yes, sometimes in order for a material name to “take” in Hexagon, we have to use the “Enter key” to validate it ... and don’t worry about that little window going blank. Just turns more hair grey. Everything is fine when the next shading domain is picked.
And people talk about Blender being difficult to learn, clunky and not doing things ‘right’...
Yeah, it may mangle group names on occasion, but I’ve never had that kind of trouble.
The only piece of advice I had, was covered…unique names…that’s one thing I have learned about Hex, so far…it doesn’t tolerate ‘sameness’ very well. If something isn’t named clearly and uniquely, it dumps some default moniker on it…