Outback FM80 stops charging but other controllers continue

I'm new to solar and just had my system installed in mid-July.  I had one company do the main installation but I wasn't happy with their service or warranties and got another company to install additional panels and system components.


The first company installed: 

• 24-300w VMN polycrystalline panels (3 in series and then 2 series in parallel I think) panels install in the south
• Midnite combiner with 30A breakers (I think)
• Midnite DC Lightning arrestor on combiner box
• 2 Fungpusun FM80 charge controllers (Outback FM80 copies)
• Midnite Mini disconnect box with breakers
• HP 10,000w inverter (factory manufactures for Aims)
• 24-6V 225AH AGM batteries - 3 strings of 8 batteries per string (Deep cycle 7.3v - 7.5v)
• Ground rod (I also have ground rods at the meter as well as connected to the main panel box for the house)
• Manual change over switch between utility and solar power

I soon realized that the batteries were being discharged too low (46v) and between the daily load and what the panels produced there wasn't enough energy to fully charge the batteries.  The HP inverter by default would switch to utility power at 47v and the first company said the settings couldn't be changed.  I decided to buy more panels and am toying with buying more batteries (but am worried about there being 4 parallel strings - one UK website suggested using busbars to connect the parallels), however, because I was dissatisfied with the first company's service I decided to go to another company. 

In between these times I had an electrician install another panel box into which I had circuits that I wanted to run on utility power put.  I also had a manual changeover switch installed to switch between solar power and utility power for a 20,000 BTU solar hybrid mini split air conditioner.  This uses about 10 kwh per day and runs mostly in the day (during the summer) so it was also preventing the batteries from being charged completely.  I put in the switch so that I could change the power source between solar and utility power once I got additional panels and batteries. 

The second company installed at the end of September:

• 12-305w Intenergy polycrystalline panels
• Midnite combiner box with breakers
• Midnite DC Lightning arrestor on combiner box
• 1 Outback FM 80 charge controller
• 1 Outback hub 4
• 1 Outback Mate 3
• Midnite AC lightning arrestor
  
• Midnite breaker box for disconnecting the batteries
• An auxiliary connection to one of the Fungpusan controllers to an automatic changeover switch to switch from batteries to utility power when the batteries are at about 40% depth of discharge.

I installed an Outback RTS on the battery bank.

So far for October we have been having cloudy days with rain in the afternoons.  My issue with the Outback and its copies is that despite setting the values for Absorbance (58.9V) and Float (54.6v), one of them will always show its state as "Absorbing" when the voltage is not at the set values and have absolutely no current flow to the batteries - no charging while the other two will still be in bulk charging mode.  Looking at the Mate 3 graph I can see a distinct break until the battery voltage drops low enough to prompt the rebulk cycle.  Sometimes one of the charge controllers, usually the Outback will show "Charged" when the batteries are not at the Absorbance voltage, but above the value for float.

I tried setting the Mate 3 for all three to go to float when one is in float but it hasn't worked.  I've calibrated the battery voltage readings to be the same (on the Outback and one copy) and to -0.1v on the other copy.  Can't get it any closer since it's at the maximum allowable to be subtracted.  Ideally I would like all three to continue charging until the batteries have gone through the absorb cycle and into float which should occur in the morning hours to mid-day if all three continued charging.  Today for example, the Outback produced significantly less energy than the copies - 6.9 kwh compared to over 10 kwh for each of the copies!  At 10 am, the Outback was producing more energy than the copies then it started slowing down at 11 am.

I experimented for 2 days with setting the absorbance voltage on the Outback and on one of the copies to 60v and it allowed them both to continue charging, however, I was concerned about over charging the AGM batteries and changed it back to 58.9v (my multimeter shows that the charge controller voltage is out by 0.4 - 0.5v).  Battery temperatures reach a max of 32C - I have a fan directed at the batteries to help keep them cool - I live in the tropics where normal air temperature is at least 30C every day.  I have the temperature set to wide with the lowest value set as 57.4v.

Is there anyway that I can get the charge controllers to keep charging (during the morning hours) so that I can get all three to go through a complete absorbance and hopefully float?