Unlucky if both fronts have punctures, would think it more likely to be leaking around the bead.
What rims are you running? Are they suitable for tubeless tyres? Presume no tubes used, not recomended on a 50 series tyre! Lots of poor roads/kerbing can cause problems with such a low profile tyre. Most likely cause in my opinion is a build up of rust/corrosion on the bead of the rim giving an uneven surface so the tyre cannot seal 100%. Very common on old rims, both steel and ally. A trip to the local tyre centre should have that sorted no problem. And I know I am a pedantic, fussy old sod, but I do hate this oh so commonly used term 'slam tyres', it is not a tyre size! :wink: