The easy way to find out is to send it back for the professional honing and then shave with it "out of the box" the first time, ie- without stropping. If there is a noticable improvement, you know it was a dull blade that caused the problem. If the problem returns after several stropping sessions, you know that your stropping is the culprit. If there is no improvement, you know it is in your prep or technique.

rs,
Tack