what are u guys using with your muffs. these pedals are very picky about what other pedals go in-line with them whether they are engaged or not, truebypass or buffered. last week i put a wah at the front of my pedal rig and it seriouslty affected the volume of my muff so i took it off and all is fine again. i also use a pog2 with it to but i can only get a good sound from my muff if the muff goes after the pog.
its also a good idea not to go crazy with the tone knob as if u go past half way u are in danger of compressing the sound too much and so losing volume.
tbh its about trial and error, getting the balance between what sound u want and the compromises u inevitably must make to achieve that. this is something only u need to be happy with if it works for u then thats what matters .
hope this helps. but if u are using a muff on its own then maybe your muff is on its way out or needs a service