Are the led bulbs a new addition ?

Odd.
And it just started doing that ?
I know some games of that era will ghost ..
But if it never did ?

check that socket voltage tabs aren't touching/bridged to ground or something like that

On the daisy chained row of sockets on the sword. I'd say you have voltage leaking in from somewhere else.

I have a similar issue with my Black Knight. I replaced the incandescent bulbs with white LEDs, but I decided the look of red LEDs would give it more pop. I put the white LEDs into another machine. Later, I noticed a similar issue as this with the red LEDs. I bought another set of red LED bulbs and it's exactly the same. Were you able to figure out what the issue was?

Your transistor for the row of lights is likely blown on the board. I had this on a Jackbot.

EDIT: Looking at the lamp matrix you've got issues on all of the rows and columns. Likely not a single transistor, so maybe the Lamp Matrix 6820/6821 PIA chip at IC10, which is above all those transistors and would affect everything as you see.