Adjusting SENSITIVITY level for a nice sweet spot is key to using the Envelope Followers on Q-Wah and ModFilter. Try lowering SENSITIVITY as 100 is usually too high. I find for a stratocaster with single coil pickups, 50 to 65 works for this parameter.
It will of course depend on playing dynamics, type of guitar, etc. as it's based on output level. Experimentation is necessary.
HINT: try BassWAH for TYPE on the Q-Wah algorithm, works great for guitar at times.