The issue I was having is that after a hard landing from a specific jump, the power to the motor would cut out for 4 or 5 seconds. The steering servo never lost power.

The esc is practically new with this being the 3rd race on it. It was in my Xray XB4 and I was racing on a small indoor track. The jump was not all that big and my 2wd would do the same jump with no issues.

Anyone have any ideas of what may be going on?

Was the ESC the only thing changed at the time, i.e. same motor, etc.?

If it was, there are basically only two general answers for R10 issues - try a new sensor cable as the R10 is very, very sensitive to those and the classic "send it in..."