I’ve had a similar experience.
As Brennus described the clearance may be the cause.
I concluded that inflating the tire adds to the problem. Slightly pushing the valve when attaching the pump makes room for the tube to fill that gap. When fully inflated it might not move back out of that position. I had very specific marks on my damaged tube each time.
I changed the way I attached the pump to the valve (holding the valve in place and attach the pump carefully, reattaching the pump more firm once the pressure in the tube was high(er)).
I had two tubes fail at the same time in proximity to the valve after about 1k miles They looked like snake bites. I recently added a nitrile membrane between the tube and rim opening for additional protection and possible pinching issues
I didn’t see this thread. I’ve had this happen! And my advice from Silca was that when you push your pump chuck on, don’t use much force. If you’re pushing the valve stem out towards the tire, that flexing will eventually cause the holes. This could be avoided with a tubeless nut, but if you don’t use an extender, the Silca tubes don’t have a threaded valve stem.
