As I suspected your comments were "spot on". This was my first time to use this genoa, as I've been using the 110%. So, after switching to the 110 because of an hour or more of frustration at not being able to tack to port, there was no further problem tacking.
The area in which we were sailing was a large, tidal creek off the icw. And yes there is tidal influence, Bob, that probably made a difference in the port tack maneuver. The starboard tack was well out of the main channel of current. So while I suspected wind on the big sail, it was probably current stalling the bow, then kicking the stern around and forcing me to gibe to gain the upper hand.
Also, the maneuver was closer to the land (shoal) bank than the starboard tack and probably did disturb the wind direction and intensity more than I thought.
I do have the original rudder, so maybe it is time for an update. The motor is a 4 hp mercury, and we both sit well forward in the cockpit, usually, and were yesterday. It's so hard to put everything in your scenario, isn't it.
Again, thanks to you severally for your input and suggestions. It will help me be a better sailor.