I repeat--

But have you done the simple expedient of swapping out extension cords yet?

(sigh) Sorry, but *I* can make a giant list of all possible
combinations and permutations or circuit breakers, circuit breaker
TYPES, extension cords, number of strings, WHICH strings, internal
wiring, ambient temperature, time between applications of loads,
etc. ...

then, try ALL of those variations to find the one(s) that work and
don't.

That's not troubleshooting. That's what (inept) mechanics/plumbers/PC
technicians/doctors/etc. do day to day:


sorry but that is a part of troubleshooting
Swapping around parts that you already have can be a very efficeint troubleshooting technique.

If we told you to go out and buy all new lights and new extension cords and new breakers and replace them all, that would not be troubleshooting, that would be shot-gunning.


If you prefer a more analytical approach, then go out and buy a dual trace oscilloscope, clamp on current probe and other assorted test equipment and we get then gather enough data to decide exactly what the problem is without swapping parts.


Sounds like we have nothing more to offer you in the way of help.

Be sure to come back and let us know what the answer turns out to be.

Mark