workout functions working differently between Epix 2 and marq 2 on 11.28 update

I'm using the half marathon training plan and have noticed that the functionality between the Marq 2 athlete and the epix 2 are different when doing a workout after updating 11.28 on both devices.

After the update, when doing a speed workout on the Marq 2 it automatically moves from warmup to 3 minute sprint without having to hit a button. This was a change from the 11.25 (and other versions) where after the warm up was complete, you would need to hit the lap button to begin the timed run. 

When using the epix 2 (also on the 11.28 update) the functionality continues to work as normal where after the warm up, the lap button must be pressed to initiate the timed run. Both watches are setup the same and use the same watch face so I'm not sure why this is functioning differently.

The other oddity I have noticed after the update is that the marq 2 doesnt seem to register the heart rate as accurately as the epix 2 after the 11.28 update. When doing a workout, i had the marq 2 on and was seeing the heart rate was around 132 (i could tell it was much higher than that) and when switching to the epix 2 (on the same wrist) the heart rate jumped up to 172 (which appear to be closer to reality). 

Both watches are on the same platform so im not sure why after the update they have a difference in functionality, any clarity around this would be much appreciated