I now did some testing & debugging. But... I couldn't reproduce your problem!
This is how the bow-thruster should work:
The thruster runs as long as you press the button.
It will disable temporarily when you press the button too long.
However: The button will stay "green" after you release the touch/click. That may be a bit misleading. (The reason for that is that the button still has the "focus".)
For testing, I found it best to move to the front view and listen to the audio. (Bowthruster sound)
I checked the bow-thruster code and it should work well with touch and/or mouse.
Does this problem still occur? And does the bow-thruster actually keeps going or it is just the button that stays green?