Auto targeting pk problem

[tohowalk]

I have a problem with the position keeper using auto targeting. I encountered a small convoy traveling at 16 knots. I sank one ship and damaged the other, went deep to reload, and got ahead of the damaged ship. It is now running at 6 to 7 knots, but every time I lock on it with the periscope, the keeper shows it still running at 16 knots. If I turn the keeper on, the white x on the attack map runs way ahead of the ship. How do I get the thing to reset so it will pick up the actual current speed? I have tried a save and reload, and that did not work. Turning the keeper on and off does not work. Changing targets in the periscope and then going back the the wounded ship does not work - the keeper insists that the ship is running at 16 knots.

SH4 1.5
TMOwtw