Wayne, First video, watch string hand. You draw back then let that hand settle forward to your facial references. This kills your back tension. Try to just draw as far as your anchor references , don't let that hand move forward!
Second video, watch the string elbow. See how it moves forward before your release happens?? That is caused by letting the hand move forward as noted above. A "creeping" or "collapsing" release is the result.
I'd suggest that the string hand should move back, stop on the face (NO forward movement) then continue back for the release.
Arne