[propbeanie]

When both vessels are neutrals, you will not get reports. This is why TC does not drop when you are playing during the "war time", when you are watching the NavMap at 1024 or whatever TC, and you'll see a green icon flying across the screen, and foof it's gone... still at the same TC and no interrupting report. Do you "physically see" the vessels yourself from the bridge in your examples above, though?

Also, as to the spawning, once you are within potential "sight" range of a spawn origination, the game will not spawn anymore groups or units. In fact, the game seemingly considers sonar range for the RGG, so you might have to be over 52+km (roughly 30-32nm) away.

Also, don't forget that the game only uses one sensor at a time...