The attached masnory fixing seems to be incorrect, too low.

Thank you for your enquiry and PE files. Certainly at first glance your shear loads do seem to be providing you with a high overstress. Now I modelled your criteria separately and attach two PE files and those files reflect what I would have expected in terms of the shear capacity. The anchor diameter has remained at M16 but with a shorter 50mm embedment depth additionally I've also used the 16Nmm2 UK masonry unit (I'm assuming this due to the Flemish bond selection) rather than your initial larger European and stronger 20Nmm2 unit. I would have expected similar results for this unit for your shear. As for your original files I'm not sure hat has happened there whether you had accidentally corrupted a fie whether that be via an internet drop or reuse of an older file or somehow getting something stuck in the memory whilst it ran the calculation or by trying to force something through. Hopefully though these new PE files will assist.