Hopefully you have your files saved but I think you're gonna have to reset to default. I would contact Ultrasabers first obviously but I have a feeling they will tell you the same. Did you run the diagnostics tool?
Yes I do. Have saved copies of the current fonts as well.
I'm probably going to just clear and replace the one font that I think is actually causing this before factory resetting the saber.
Diagnostics came up clean.
What I think it is, is that I'm working with near duplicate font-packages. Clones, if you will. The Arctic Blue font was built with the express wizard, then edited to introduce the flicker, saved to disk. Then I cloned it by loading the disk saved font, and editing Power LED levels, but leaving the sounds (and effect names) strictly alone. That's where I think the problem lies, with the saber reading the clash effect for the CB font and being redirected to the AB hum. The change on extinguish and re-ignition may be because the saber gets confused by the package shift, and defaults to the package it ignited from previously (the Purple mute).
Think I'm going to save and quarantine the flicker fonts involved and wipe the CB font from the saber and start again. If I can reproduce this, US has got a starting point for whoever does their soft/firmware troubleshooting and revision.