If not above 6bm then the post drops in frame or saddle rotates.
See the news story about the clamp from BikeYolk.
Have you tried carbon grip paste?
Tried carbon paste , failed! post does seem quite baggy in tube
What frame is it, and does the dropper match the seat tube size?
Orange p7 , the dropper size is the correct size .
How does a standard seatpost fare below 6nm? That will give you a clue as to whether it's a seat-tube issue or a post issue.
Good call I’ll pop in a normal post
I had the same problem on an old 27.2 dropper - I think to get down to size but keep the internals the tube wall is much thinner
Anyway, a combo of carbon paste and one of these style clamps worked, I figured it spread the clamping force to reduce pinching..
Have you got the split in the clamp lined up with the split in the seat post tube?
I’ve found if it’s opposite you can’t clamp up the post sufficiently
Hope that makes sense.!!
I have the same issue on one of my bikes so I’m following with interest...
Update, removed seat clamp and the post moves around like it’s in a wizards sleeve . Orange have been ace and accepted reaming may be wrong and are replacing the frame .
Not a bad response, I was about to suggest somebody with a micrometer to check both out.