Geez, sorry I need so much handholding. The 120 ohm R15 resistor does not glow or spark when the tube is removed. Just to be clear, it starts glowing first, then began to spark, like a small fireworks sparkler. It’s quite … sparky.
I also took a look at the solder side of the board, and there doesn’t seem to be any connections from R15 to nearby soldering points.