I’ve recently converted to carbon rims and I seem to be having a lot more flats than normal.
Its an xc race bike so very stiff and light, I used to run Mavic crossmax SLR’s and didn’t have much problem with flats and I would consider this a stiff wheel. Is there a common problem with stiff (carbon wheels) and punctures?
I’ve run Stans Crests with no problems either.
I have had the problem with tubeless and as well as with tubes.

Is this common?

what sort of punctures – snakebites?

I think so.

Can’t say I noticed any difference. Stans are sometimes said to be a bit better with pinchflats because they’re pretty soft and round- basically the easier it is to deform the rim the harder it is to pinch, but that’s got it’s own disadvantages… I wouldn’t think the same applies to the mavics though?

Rim shape could play a part but my LB rims have pretty rounded edges

I presume you are running them with tubes. Why not give tubeless a go?

I run them tubeless, then punctures when I was out and about and then put a tube in to get home. I left the tube in for a few days and then punctures that before I set up the tubeless again.