Wicked. phantom load!

Welcome back Mike!

I am guessing the 1.1 Amp @ 24 volts is not the phantom load itself, but the Magnum inverter not going into search mode (25 Watts running, 7 Watts search):

https://www.solar-electric.com/lib/wind-sun/MSH-RE-specs.pdf

So... It is possible that your phantom AC loads could be capacitive (or even inductive)--If you have something plugged in that has line filters (capacitor network), you could be getting a current that is out of phase with the AC Voltage sine wave (capacitors have a +90 degree phase angle between voltage and current). This all gets down to that, technically, your AC loads could be drawing zero power (PF near 8.0), but you could still be drawing current--5 Watts (or possibly 5 VA--which "ignores power factor), could be keeping the inverter awake.

Has anything changed? Is this always been happening, or did it just start? Did you change an inverter, add a (typically) electronic load (computer, laptop, TV, etc.) that may be drawing power.

Do you have a Kill-a-Watt type meter... There is the Amp (and VA) modes that could help debug.

Things to try:

Unplug the power strips and any other loads one at a time (and/or kill breaker to each circuit) ... There are "filtered" power strips that may have capacitors for noise reduction, and could be drawing more than zero amps.

Try setting the Inverter to 10 or 15 Watts for search mode (I presume you can program the inverter?). And see if it will go into sleep mode. I have seen the small 300 Watt MorningStar inverter with 6-7 Watt search mode... Larger inverters seem to default at 15 Watts (the few I happened to check specs on recently). It is possible that the inverter may not reliably detect 5 Watt even if loads are less (than 5 Watts) at that search setting.

Regarding your solar panels... If you have just one string, you can test Voc and Isc on each panel (disconnected panel measure Voc--open circuit voltage; and short the panel with a 10 amp DMM or a DC Current Clamp DMM and measure Isc--Note, if MC4 connectors or similar, avoid connecting/disconnecting under load (or short circuit). Throw a dark tarp over the panel before plugging/unplugging. MC4 connectors can be damaged if arc'ed).

Note that Voc is almost always at full voltage with any sun on panel. Isc is proportional to the amount of direct sun on panel. On clear/sunny day with panel pointed at sun, should be close to Isc (technically, I would say >50% of Isc). If have more than one panel, check each one for Isc quickly, typically you will have a mix of good and bad panels. Good panels will have the same Isc measurements (within 10% usually). Bad panel will be much lower (typically 50% or less).

If you do not have a DC Current Clamp DMM, I would suggest you get one. They are the cats meow for debugging and understanding DC power circuits. There are decent ones at $100, and even "good enough for our use" at $50 on Amazon. Here is a sample link or two to start your search:

https://www.amazon.com/gp/product/B019CY4FB4 ($100 version)
https://www.amazon.com/gp/product/B07546L9RT ($50 version)

The problem with off grid systems, is that the charge controller will limit solar panel current if the battery is not discharged significantly, and/or if there are not big DC loads on the battery bus.

If you have other strings of panels, then you can compare between the various strings and see what the rest are doing (assuming they are good). Which also raises the Vmp-array and Imp-array voltages for the various strings. If, for example, the Vmp-string between the BP and other parallel connected panels is >10% difference, then an MPPT controller cannot effectively get the best Vmp/Imp of each string.

Then there is also the fact that many BP solar panels had problems with the J-Box connections... Here is a website that lists models that are under a class action claim (scroll down and click link to see affected models):

http://www.bpsolarsettlement.com/faqs

You can go to the home screen of the above website and see some major failures.

My panels did fail too, but I caught them before that got "that bad". Basically my Imp fell to 50% less than I typically saw (on my GT system), and if you looked close to the glass side of the panels above the junction box, many of the panels showed a light "coffee colored" stain over the J-box (from overheating).

-Bill

I did not see that the controller was in bulk... No voltages on the battery bus/details/etc.

-Bill