My 2021 Transcend that I picked up in December 2020, included the solar package with 165W Furrion solar panel and this Furrion MPPT 25A charge controller. Also, I had the dealer throw in a 2nd battery (basic Interstate). Trailer was plugged in the first couple of months, but hasn't been for the last month or so, and I've noticed battery readings different than what I would expect when I casually check with my handheld DMM. I recently installed a basic battery monitor and am more closely checking the behavior. (Unfortunately, the battery monitor doesn't keep a history, so I'm having to spot check. Nor does it indicate current direction - charge vs. draw). Here is what I've seen so far.

Several weeks ago - observation that made me pay more attention (before battery monitor installed)
Battery reading = 12.6V
-I don't recall if battery disconnect was in on or off position, but even if "on" (i.e. connected), everything that could be turned off was...including fridge. So current draw should have been very low. Weather had been decent, so I would surely have expected solar to keep batteries fully charged. In fact I would have expected to read the float charge level specified in the manual (13.2V). This reading was during the day on a sunny day. Charge controller is set to correct type of battery, and main LED was blinking green indicating it was charging (per the manual). In poking around, I physically disconnected the battery terminals and looked them over. When I physically reconnected the battery, I then measured 14.3V, which is what the manual shows as the "bulk" voltage level. So, it would appear like physically disconnecting and reconnecting the battery reset something in the controller, and then it started charging. That doesn't seem right.

Yesterday - with battery monitor installed
Battery reading = 13.2V (float level), fluctuate between 0mA - 100mA (I'm assuming that is how charge controller maintains float level)
Checked around noon, partly cloudy
Battery disconnect switch set to "off" (i.e. disconnected), so there shouldn't be much if any current draw

Today
Battery reading = 12.9V, 0mA
Checked at noon, overcast sky.
Battery disconnect switch set to "off" (i.e. disconnected), so there shouldn't be much if any current draw
Main LED blinking green on charge controller, indicating it thinks it's charging as normal
It would seem to me the charge controller got back into the non-charging state for some reason. I would expect it to still be generating a little bit of power even with overcast skies.
I set the battery disconnect switch to "on" (i.e. connected), so see if that draws the battery down. As expected, current reading jumped to ~115mA. Thinking maybe charger won't re-engage until battery drops to a certain level. But I don't think that would be desired behavior.

I'll check again later and post my observations.