B&G h2000 to Raymarine C90W interface problem

[bewitched]

I wonder if anyone can help:

Set up: B&G h2000 instruments are providing instrument data (boatspeed, compass, depth, wind) to Raymarine C90W unit via NMEA0183.

Problem: Heading is frozen on chart plotter (i.e. the black boat icon does not rotate as the real boats' heading changes). The Heading data does not change in the data bar either. It always reads the heading that the boat was on when the unit was first switched on.

I know that the B&G information is getting to the plotter as wind, depth, speed data etc is all repeated correctly on the plotter.

According to manuals B&G sends HDT, HDM & HSC and Raymarine reads HDT, HDM & HDG. I have tried displaying both True & Magnetic, but the problem remains.

Any ideas for a fix?

Is there any way within the C90W unit to tell it to use HDT for heading for example?