Una corda and double damper lift

[paul bruesch]

A client has a Young Chang TG-150, mfg in 2000. When I press the shift
pedal, it doesn't go down very far, and the action does not shift far
enough to play only two strings. I adjusted it so that it would shift
farther, but then the dampers of the wound bichords to the right of
the break (there are about eight such notes) would lift in pairs...
for example, playing D3 with the shift pedal down results in dampers
for D3 and D#3 being raised. This only happens on those eight or so
notes, not in the plain wire treble, nor in the wound bichords left of
the break.

Any ideas?
Thanks,
Paul Bruesch
Stillwater, MN