A034 NMEA2000 wind data fails on Garmin chartplotter

[chiko]

I have a number of Raymarine Seatalk1 instruments + AIS which are input to an A034 which is connected to a Garmin Echomap 65CV chartplotter via NMEA2000. Some of the N2K data is accepted by the Garmin (HDM, DPT, MTW, AIS). However apparent wind data fails to appear, as shown in the attached screenshots. To confirm that the fault is peculiar to the A034, I connected the NMEA0183 data output by the A034 to an Actisense NGW-1 which then converted it to N2K. With the NGW-1, the Garmin works as expected. (The NMEA183 MWV strings look fine and work in OpenCPN.) Clearly there is something within the Quark PGN, or missing from the PGN, that Garmin objects to, or is pedantic about. (Going back the other direction, the NGW-1 is more tolerant and can read the A034 N2K wind data.)
A typical NMEA183 string is: $IIMWV,129.0,R,8.1,N,A*3E

Wind is important on a yacht. I first raised this issue with Quark in October but have not yet received a meaningful response, so I hope this additional detail will stimulate someone to look at it.

Also, the water speed does not appear on the Garmin via N2K.
A typical NMEA183 water speed string output by A034 from SeaTalk1 (with boat stationary) is :
$IIVHW,,T,,M,0.0,N,,K*7B
$IIVHW,,T,,M,0.00,N,,K*4B

[admin]

Hi Chiko,
I will forward your information to our engineering team and reply asap. Thanks for your patient.