Fenix does not update Training Load data from other sources

My Fenix Training Status doesn't account for Zwift or Sufferfest data even tho the data is in Garmin Connect.  Why doesn't Garmin Connect recalculate the data (for example Training load) then provide that to the watch.  I do not want to be recording on the watch when I'm using an Edge unit or indeed Zwift or Peloton.

This is frustrating as I like to look at training load as a motivation.  

It updates Last Sport accurately so why can't that be incorporated into Training Load? 

It doesn't seem that hard.