Welcome Roger, you may be surprised to discover both sets of instructions are correct.
Since dozens of cooking events with uneven results have left you totally confused, give up and enjoy your fried filet. For this cook, frying (sautéing) is always the superior cooking method for filet mignon. By attempting to understand the SV technique you are obviously wasting your time, efforts, and expensive food. SV cooking isn’t suitable for all cooks.
Seasoned Community members will immediately recognize the folly of comparing cooking times of sirloin steak to a sirloin roast and not recognizing the distinct difference and resulting cooking times.