Why does my watch NOT light up When i raise my arm

Check you still have Wrist Raise enabled in the Watch app on your iPhone (My Watch/General/Wake Screen) and check the watch orientation is correct for the way tou are wearing it (My Watch/General/Watch Orientation).

If that doesn't find the fix, try a Forced Reset. Press and hold both buttons until the Apple appears and the watch begins to reboot.

If you have checked the settings as I suggested, and rebooted the watch without fixing the problem, the next step is to unpair and erase the watch, then re-pair to your iPhone. This will reload all the software and settings in the watch.

I did the reset and I still have the same problem of the watch not coming on when I raise my wrist!