I agree. Find a way to enhance the bottom or see if there is something causing a lack of Bottom. You should only have to turn the Volume up to and 12:00 or half way and no further to have proper volume.
The Sriracha Fuzz does not have an “Active” tone control so the circuit cannot ADD high frequencies.
The problem is likely due to the lack of Bass so that when you turn the volume up you are only hearing the LOUD high frequencies.
Same as if you turned up and old transistor radio really loud. No Bass = Loud Highs.
There could be many causes for that issue. I would try only the Sriracha by itself and not hooked up with anything else. There is simply no way for the Sriracha to Boost Highs only.