@moose89 I’ve been doing this stuff for over 45 years. That’s a new one on me.
FWIW, usually anything other than the filament being lit and a light blue glow just on the inside of the glass when running, any ’lights’ or other phenomena inside a tube suggest a Bad Thing is about to happen or will happen soon. If you have another tube that isn’t doing this while this on is, that says to me that a Bad Thing is looming.