DAB Radio reception issues when OVMS plugged in

Hi,

any suggestions for the following issue?

DAB stations cut in and out.

With the modem card installed, even strong DAB stations are difficult to receive. Unplug the OVMS and the problems goes away.

With the modem card removed, strong DAB stations can be received OK but week DAB are difficult to receive. Again, unplug the OVMS  and the problem goes away.

Ferrite cores on the ODB cable do not fix the problem.

Relocating the cellular and GPS antennas did not fix the problem.

Mark