I don't think the inverter, just staying on overnight would consume enough power to take your batteries off 100% but, I'm unsure what is going on at night. You don't use any power at night? That is why most people get batteries, to get them through the night. You don't have to, some like to keep full batteries for power failures.. I get that.
I think setting #14 is what has got things working differently than you want. Setting 14 as "SNU" uses BOTH utility and solar to charge your batteries at the same time during the day. Using this setting can be confusing, and explains why you reference setting #2.
Before I can offer suggestions, I guess I should have asked what your using this setup for? What I mean is, if you want it for just backup power source, or for off grid type use, or both with utility savings, or whatever you want?
The #14 setting is the one that will cause the most problems, due to the complexity of using both grid and solar to keep batteries charged, and at what point does the battery cycle start and stop and with which power supply at what time of day/night.