Same issue for me, just completed a grav survey and whilst i had a message to say the survey was complete no messages about no more orders for the survey ship in question
It is obvious a widespread problem - I am just struggling to reproduce. Maybe I already fixed it without realising
Here are steps to reproduce this problem in C#:
1) Have a system that has already been geo/grav-surveyed to completion.
2) Put a geo-surveyor and a grav-surveyor in that system.
3) Set standing orders to "Survey Next Five System Bodies" for the geo-surveyor and "Survey Next Three System Locations" for the grav-surveyor.
4) Progress time by a day.
5) Reproduced: No messages alerting the player that the standing orders are unable to be fulfilled.
This can sometimes results in a lot of survey craft ending up in space doing nothing for months or longer at a time before the player realizes, meanwhile ship maintenance clocks are ticking up the whole time. It's rather annoying.
In VB6 there was a message like this in the log:
Also keep in mind that many players set up their survey ships to perform dual geo/grav surveys with their standing orders like this, which might require extra handling: