Not to throw anyone under the bus here but it's a combination of bell cranks (backcountry) and flaps (Keller/performance) are not symbiotic. The backcountry wing is incredible. The flaps are incredible. The two need to come together and make them what they are. i can count at least 7 people that have or have had the very same issues.
We re-rigged ours adding a longer push rod, tightened the cables and added an inch at the bottom of the flap handle. Love them now.
Just spent the weekend in Austin with Pops at his flying landing on 10,000' plus peaks all weekend!
Heres a steep downhill departure from 10,300' with DA of 12,700'...no joke
https://youtu.be/HfGLatJ6qi8