Africa Twin front tyre punctures- abnormally high incidence

I have had at least 5 punctures on my front wheel over a 18 month period. I know a few other AT riders that have had abnormally high number of punctures on the front wheel too. I took the factory fitted tyre off on day one plus I fitted heavy duty tubes- done by fitment center that I have used for many years. Current tyre is Mitas E07+. I had 2 1200 BMW GSs and never had one puncture riding similar routes to those done on AT. I know there is a certain amount of chance involved when getting punctures, but this frequency is beyond bad luck. My theory ( not based on any technical reasoning) is that the rim design is contributing to punctures caused by heavy impacts I.e. snake bites. Does anybody have an explanation for the abnormally high number of punctures on the AT front wheel? Measures to minimize punctures taking into account I already use heavy duty tubes?