I've far fewer problems the past couple of days after hooking up directly to the modem instead of going through the router, and then switching back again. Perhaps the process o rebooting the modem and router a few dozen times trying to figure out the problem resolved some communication error.
With that said, I've only had fewer problems, not resolved everything. I used to get the "retry" screen several times every hole. Now it only happens 3-4 times per game. So, I guess that is an improvement. Instead of being at "wit's end", we'll say I'm now at "wit's mid-point". If it continues with only a few drops per game, and lets me back in immediately without having to close the game window, it is at least playable.