Don't try measuring the tube voltage or current right at the HV
leads!!-- the circuit is very unfriendly, with wild voltage and current
peaks. It's likely to overheat your meter's voltage dividers and.or
the inverter.

You might have too high a current if the HV wires to the tube or the
tube itself are too close to any nearby metal. Try running the wires
EXACTLY as the used to run. Be sure the tube is EXACTLY where it used
to be, no closer to the LCD panel or the reflector tape.

you might also check the 22pf or so capacitor or capacitors in line
with the HV leads. If they short out, which is quite common, the
tube will run at really high current.