That honestly sounds like a bug, reset the memory for a mix to
work?
I have just run into the same issue as the original poster.
I have in pmix 2 rudder and aux2 mixed and linked for a
2 servo push pull rudder setup.
I want a throttle to rudder mix for downlines on a 35% Extra.
Pmix 3 is set up as Master -throttle, Slave -rudder, the link option
goes blank. and only one servo will move. It does not work properly.
I had do the same thing the original poster did.... add Pmix 4
Master -throttle, Slave -aux 2 and set it up identical to pmix 3 to
get the proper rudder mix.
ORIGINAL: Bax
We did Pmix4 first, then Pmix5 second and had all features on both mixes. We used the same channel assignments, but we also started after we cleared the memory because we'd been messing with the other mixes earlier for another customer. We usually try out our solutions on a 'clean' model memory.
The LINK or TRIM options will turn on or off, depending upon the master channel and what other mixes are set up first. If you set your mixes up the same way, but just do 4 first and 5 second, it should work. You'll still probably have to do a reset of that model, though, to get them at the defaults so that prior programming doesn't confuse the issue.