NCAA Clock Question

[SC Official]

For all NCAA gurus

When there is a first down or a player goes OOB (not under 2:00 in either half), when is the clock actually supposed to be started by rule? Watching ACC-officiated games, it is very obvious that the white hats do not wait for the CJ to put the ball down before winding the clock–in most cases, the clock is only stopped for a few seconds before the R is winding it. But I'll watch other games in other conferences on TV where the R will not start it until the ball is set down by the U/CJ.