If one of the INS units does not have a track initialised, it will not show wind data when that mode is selected. It should, since the only data required to compute this is the aircraft heading vs the sensed track.

This one is kind of by design as a sim-ism for both stability and performance reasons.

The entire INS computations/detection logic is inhibited unless user does a TK CHG 0 (P.POS) to another waypoint to initiate it.

Interesting, ok! Good to know.