In the unfinished shop side of my basement, I have several cheap hanging florescent shop lights. In the winter, they go on immediately. As soon as the weather warms up, about half take several minutes to light up. They light right up if I run my hand along the tubes. Up until last year, they all would light up immediately when switched on. Voltage reads 119.2 at all outlets and there have been no changes to the electrical setup. Any ideas why this delay now?