So OK ... I can't get either of two Garmin 440s to work reliably providing a VMG to waypoint.
However, my old GPS 76 ... with only a black and white screen ... ~10 year old? ... has no problems.
here's a photo of what we are trying doing so far.
Interestingly I had to recently buy a PC with ME on it to download data from a couple hundred 3.5 disks. $15.
But this now so called "legacy" computer also provides a glitch free base so that I can now load waypoints and routes directly into the old 76. Lots of things happened when MS went to xp ... and a number of "older" equipment lost support.