Sporadic behaviour is usually a sign of noise and not a phase issue.
When things won't come on as expected look at what else is plugged in. Check what is on the same circuit first.
Noisy devices don't need to be on, just plugged in can be enough in some cases.
I once had a lamp with an old incandescent bulb that would render every thing on that circuit incapable of working when on.
As it turned out the bulb was failing.