Lazy Daze Owners' Group

Ok, odd question here.

The panel that shows the tank levels (black, grey, fresh water, propane, etc.) was making a rapid beeping noise today.  It stopped some time later (was beeping for maybe an hour or more), but I would like to know if anyone knows what might cause the noise. It is a rapid beeping, almost like a chirping.

We have a 89 TK.  I could hear the beeping clearly while standing in front of the sink and when I opened the cabinet above the sink it was louder - which shows it just showed up today or we would have heard it before.  It is coming from the area behind the panel for tank levels (inside the area that is boxed in).

Things that were done recently that might have affected it...
Our black tank sensors have not been giving accurate readings, as expected in a typical older rig, it showed full/near full always.  Though I admit I have not paid attention to it the last couple weeks.
About 3 weeks ago we started using a black tank enzyme Valterra power blue
During that same time we decided to try and clean the tank out more and have been using a wand with the sprayers on the end about once a week - I don't remember the brand but it is similiar to Camco wand - at the end are 2-3 jets that spin as water shoots out of them.
Last weekend, since I can't hit the bottom of the tank with the wand - there is little room to "tilt" it - I used a garden hose attachment that had a jet on it to spray off the bottom of the tank.  That seemed to loosen up some more old stuff.
Also this last weekend, instead of the power blue enzyme, we added VALTERRA Sensor Cleaner - just cause it sounded like something good to try (not really expecting anything despite good reviews on newer rigs).

I noticed earlier today before the beeping that the black tank was showing only 1/2 full (likely accurate, though it will take a couple more weeks of usage and draining and watching the monitor to see if it is really accurate).

So my wild guess (not knowing anything about that electronics in the panel), maybe a sensor changed as it became ungunked and was causing the beeping?  And when it got fully ungunked it quit beeping?  Yes wild guesses but I can't think what else would cause the beeping, especially in a panel that shows LEDs not "alarms".
The rig has been stationary this last week, no high winds rocking it around, I was not doing any work/any unusual movements in that area that would have me shaking the components, so I don't think a wire came loose.

Anyone know more about how that panel is wired or what might make it beep?

Thanks, Jane