DS-6 as Buddy Box: Issue with DC as Master

I normally use a DC-24 (previously, at time of DS-6 tests, a DC-16) and
purchased a DS-6 to use as a buddy box for fellow club members who
do not like my tray style and prefer a hand-held style.

I created a default model in the DS-6 and bound it to the DC-16 as a Student Tx.

When I transferred control from the DC to the DS-6, each surface jumped, considerably.
No amount of subtrim / trim / endpoint adjustments could match the default
1000 usec / 1500 usec / 2000 usec of the DC.

I've been told that the R3 that serves as the heart of the DS-6 may require some programming?

Has anyone had success using the DS-6 as a buddy box and, if so, how did you accomplish this?

Thank you.
Michael