Make your D-loop be an off-center loop that will create a bit of downward pressure on the arrow by:
Nock an arrow
Slide lower D-loop knot down the string 1/4 inch
Attach a brass nocking point just below nock so it's tight against arrow(or using serving material to tie in a nocking point)
Slide D-loop knot back up
Remove arrow
Tighten D-loop knots with needle nose pliers pushed in between loop and string to create a wedge and push like hell
Problem should be solved
Unless you don't use a D-loop and clip directly on the string. In that case you must be clipping the release above the arrow, so switch to clipping in below the arrow.
Unless you don't use a release at all. In that case you must be using 2 fingers above and one below, so switch to two fingers below and one above.
If you're using a D-loop with fingers, then you've got bigger fish to fry than we can help out with.
Good luck
