just played with shared vision and after accidentally closing the game we continued playing but somehow warriors did not attack anymore in one direction.
before loading:
A shared vision, B did not share vision but had fV set.
after loading:
B's warriors would not attack A's warriors but explorers still worked. Turrets also did not attack.
Although the mV we never touched still it was set for A at least.

the savegame attached shows the behavior. load the game. the other attacks. you don't fight back.
switch off market view (mV) to fight again.