I want to give a status update (and finale) to the AC issue. The solution to my problem was two-fold. First, I did a thorough cleaning of the battery terminals (I should have done this initially, I know). I then contacted ProSine and they gave me these instructions: disconnect shore power and disconnect all battery power, also make sure the solar panel is not working (I covered it with a blanket). Wait at least an hour (they said that in some cases it takes up to 6 hours) for the ProSine to de-energize at which time it does a "kind of re-set". I waited one hour, re-connected all the power, uncovered the solar and everything is as should be. So, all systems are go and nothing had to be replaced.
Thanks for all the suggestions and I certainly would have gone the route suggested had the above-mentioned two steps not worked.