Bug in the current ctw version. When pwarping around,
it turns off interdictor.

This should only happen if there's an Interdictor powerup delay. The point of the powerup delay is so whenever you move into a sector there's a pause before you can trap someone, but if you're already in a sector and someone else moves in, you'll be able to trap them immediately. So if you move to another sector in any way, the IG should power off prior to moving. This is true of both the IC and PIG.

So shouldn't it be turning on then after the delay? Or
do I need to manually turn on IG after every move
(because that's very annoying)?

I was just being lazy I'll fix it so it's powers down temporarily during a move, then powers back up after delay. But anyone who tries to move prior to the end of the powerup delay will be free to move.