check the EPA on channel 7 for both ends of the switch (on and off). When ON (HH mode) see what the % is and adjust accordingly, do the same for OFF (non HH mode).
Dont worry about the channel 4 adjustments.
Then flick the flight modes and see if it changes the % while in the EPA adjust screen.

see if that helps.

I used to use channel 7 then went to channel 5 because of the gyro adjustment option.
The only downside is that to switch between HH and normal you have to use 50-100 for normal and 0-50 for HH and treat the 50 movment as 100% adjustments (thats means if you wanted 75% in HH mode use 15%, or 75% for normal mode use 85%