Recently switched from Garmin to Galaxy Watch 7.

I was very confident in my Garmin's HR readings as I had verified them with a chest strap. My heart rate during a run would typically fluctuate between 170-190 bpm depending on intensity but it never falls below 160. 

My Watch 7 consistently reads between 100-110 bpm during my runs. As soon as I finish the exercise (in the watch after I stop running) and it goes back to my normal watch face where I have continuous monitoring of heart rate turned on, the reading jumps up to expected readings (140-150 bpm) as I've stopped running and it's on the decline. Also seems to me like it's the exercise app in phone that messes with it? 

I've followed the steps from Samsung.

Fit - loose, normal, very tight... no change

Cleaned just before exercise - no change

All software up to date...

Anyone else experiencing similar and having any luck fixing it?

Latest run