Qu-You App on Android & iOS - Level wheel does nothing

Hello A&H Qu community! This is my first post!

Our worship team uses the Qu-You App on both Android and iOS to manage our mixes through mix 1,2,3, and 4. Sometimes our team members assign an instrument to their mix wheel only to find that the fader does nothing to adjust the volume. Any ideas as to why this happens and how we can keep it from happening in the future?

Is it the wheel or the fader that does nothing (you mention both). If one is down the other will do nothing.

Could also be to do with mutes and/or assignments?