Sounds like a short and the switch is bypassed. Try jumping the battery directly to the driver + and -
Remove the tube, press the battery+ against the + contact on the driver. Take a jumper wire and touch it to the battery - and (an alligator clip is helpful here) the bare inside of the head (be careful not to short the + contact or battery + or you’ll release the magic smoke). See if you have the same iaaue. If you do, then the driver or switch has gone bad somehow. You can trace the fault to the switch also, but you need to remove the switch bezel and boot to remove it.
If you need a driver, any EA series driver will fit the EA01S, including the Mateminco LT40, MT01, Astrolux EA01, Ft02S, etc. You can get them from Astrolix 9r Mateminco, but they aren’t cheap.