Unfortunately the ReWie protocol used by Mixup in order to transport control your daw can sometimes be unstable.
Here are some things you should be aware of :
- Insert two instances of Mixup in differents formats, for example VST3 and AU) might be conflicting and break our connection to the Mixup ReWire device. Try and use only one Mixup plugin format.
- Try not to use Mixup in several DAWs simultaneously.
- When using Logic: Deactivate Rewire in Logic Pro X -> Preferences -> Audio and reactivate it might fix it.
In all these cases, close your DAW and reopen it. ReWire should works fine now.