I have one Hue bulb that doesn't detect. But it lights up when you switch it on.
So I went up there with a voltmeter, as it's above the garage entrance...
40 Volts AC, while the rest of the garage is getting 108 Volts. (yeah, lower than standard... we're at the very end of the line, 83 miles from the city it's being transmitted from...)
So now, ok, where's the voltage drop occurring?