Cannot live calibrate compass

i am using apm 2.6 for several years … i have few of them.
the ones that are mounted on quads / hexa i cannot live calibrate the compass.
after starting the process … nothing happends. no white dots are added … and the routine doesn’t working at all.

i tried with USB cable ( many of them ) BT connection and telemetry modems. several computers q operating systems … and several APM units.

is it canceled ? i cannot find any data about it.
how can i re calibrate the compass ?

the issue is Z axis whiggles … i am trying to solve.

thank you

Live Calibration still works in Mission Planner. I blew the dust of an old APM I have and it worked fine.