I have two aquacomputer D5 PWM pumps controlled by an OCTO, and I am unable to change the controller setting for the 2nd pump

• pump 1 stopped working (no info reported & flow rate dropped) {p1.jpg}
  
• pump 1 was set to a 'Power Preset' value, and pump 2 was set to 'Use Settings of Pump 1 {p2.jpg}
  
• with pump 1 fail, I tried to set pump 2 to 'Power Preset' {p2_pp.jpg}
  
• but pump 2 automatically reverts back to the 'Use Settings of Pump 1 {p2_revert.jpg}

Indeed, may be the cable going from the computer to the external radiator is faulty.
I plugged in an external power supply and the voltage seems to be OK now.

Unfortunately the controller works the same.
When I change pump 2 to Power Preset, it switches back to Follow Pump 1 after a few seconds.
You can see this on the graph for pump 2 (p2_new_psu.jpg)
- pump 2 runs at 100% perhaps due to due to pump 1 showing no rpm?
- pump 2 dips down when I switch it to Power Preset, which is 60%
- a few seconds later pump 2 switches to follow pump 1 again, and goes back to 100%
- the pump selection tab at the top actually switches from the pump tab 2 to Pump tab 1

I wonder if the OCTO has an issue?
I may try switching it out first as that is considerably easier.

Resetting the OCTO fixed the issue about PWM port 2 self-selecting to follow PWM port 1.
Pump 1 still looks fail, which presents the opportunity to make minor updates during the fix.