Has anyone had a problem with this where the glass curls on the surface in what appear to be hairline cracks on the surface. I've heard of this with 3" or larger but am finding several examples in 1x1's. I never knew of glass being approved for shower or wet area use, but is this a rating? I am using Mapei's Adesilex ultra white glass tile mortar.

Is this happening on an accent strip or a larger section of wall?

Is there any type of crack suppression membrane under the glass?

If so, did you use the Keraply additive with the P10 thinset?

One thing to remember, is glass tile can not tolerate much stress and strict manufactures guidelines for installation must be followed.

Glass can crack from thinset shrinkage, but that should not be the case with the P10 thinset, unless there is some other structural issue.

This phenomena was introduced to me at a Schluter workshop I attended in the middle of doing a tub surround. I noticed it before but thought they were just bad tiles. They were sporadic and probably a hundred or so out of the thousands in the surround. The tiles are over Kerdi Membrane & I used Mapei's Adesilex glass mortar.

Is crack suppression an independent type of membrane?

No it is not. Kerdi is strictly a bonded waterproof membrane. There is no flexibility to the membrane.
Schluter has stated in their installation requirements that "certain glass tiles are not compatible with bonded waterproof membranes" and to check with the glass tile manufacturer for specific installation specifications.

The P10 adhesive is supposed to have the additive when used for glass as per Mapei. I don't know if this may be part of your problem along with the use of the Kerdi.

Unfortunately, there's going to be a lot of finger pointing from the manufacturers as to whose fault this is.
It will ultimately be the glass tile manufacturer that specifies how their product should be installed. Have you contacted them?

Have you contacted your local Schluter rep for their take on the situation?

would bonderizing the backs of glass tile solve the problem, I know it is a pain to roll on this product. I installed a glass mosaic over kerdi and bonderized the backs of the glass and so far no crazing ?