1) Get yourself a
"welder's mask" plain replacement glass (usually tinted dark green ) .
With that you can always check the operation of the COB and of course check upon the diodes of the COBs..
2) If you're using Ideal array holders ,lightly pull out with your fingers all the wiring from the holders ..
None of the wires should come out loose from the connectors.
In case that a wire or more disconnects when you pull it
with your fingers ,that's a "bad connection" ,which may causing the " random flickering " issue.
Strip the insulation of the wires at least 5 mm .
If it is multistranded ,contrary to what is suggested ,twist the strands tightly together and push the bare wire end into the connector.
It should be felt like a"clicking" clamping action.
3)Check for shorting of bare wiring with the heat-sink .
...,.And/or -as the mains might be causing this phenomenon also ....
4) Install an EMI filter .
Is the CC driver earthed/grounded ?
If yes ...
...Not so possible to happen ,but it could be a reason , so ....
5) Check the mains ground/earth condition.
Specially check for -severe- mains leakage currents to earth/ground.
Cheers.