ACTIVITY not sync to Garmin Coach Plan's suggested WORKOUT.

Hi, 
I'm a new GARMIN user for Forerunner 265 (no music). 

1) ACTIVITY not synced to WORKOUT.

I have set up Garmin Coach plan for a run event. 

First few runs were recorded successfully as WORKOUT. 
But subsequent were recorded as ACTIVITY and would not sync to WORKOUT, so it's still shown as no workout done. 

I have already tried below without success:
-change training days and back, 
-change EVENT type to TRAINING, 
-select "RUN", select "DO WORKOUT" when plan suggested TODAY's. 
-updated watch software and android app.

Can anyone teach me how to get it sync-ed up?

2) TODAY's WORKOUT suddenly changed, overnight. 

Also, suddenly my workout changed for the day. I checked the night before and planned my activity for the next day. Only to wake up to a LONG RUN which i could not accommodate to. Did a BASE run instead and again encountered above mentioned issue of ACTIVITY not syncing to WORKOUT. Now shown as UNCOMPLETED (TO DO). Presume got to do with adaptive. Had a gd deep sleep. Any advice?

Thank you in advance!