After checking the parameters for Trace Bitmap, there is not a button marked "OK" to start the trace. There is an "Apply" button, but that doesn't actually do anything that I can tell. All documentation (and I've looked at more than a few) says to press the "OK" button. The question is, how do I start the trace function.

Select the bitmap and hit "Update" to get a preview - when satisfied hit apply.

Tap apply and wait a minute.

The trace is placed on the original.  You would have to move the trace off of the original to see it.