The Ancient Survey Module (first screen snapshot below) says that it allows you to give any ship the ability to survey anomalies.  However, what it doesn't say is that the ship will lose that ability after some number of turns.

The second screen snapshot below shows that I have given the ship named The Lash the ability to survey anomalies on turn 89.

However, the third screen snapshot below shows that the ship has lost the ability to survey anomalies sometime on or before turn 122 (I am not sure exactly which turn it lost it on).

If the intent is that the ship will lose the ability to survey anomalies after some number of turns, then you should say so in the description of what the module does and there should be some kind of countdown visible in the ship description.  If you did not intend for the ship to lose the ability to survey anomalies, then you have another bug to fix.