Interesting bug just happened to me related to Chinese outposts. It seems that towers are shooting a way less than they should to and before they are destroyed they dont even shoot at all. Handcannons were upgraded on both of course.
Dont be confused by sound because there are much more outposts nearby.
I think it might be related to berry bushes nearby (they cause to crash your game when u try to place landmark between berries+gold or stone) so I would not be suprised if they were even behind this.
U can clearly see that there are no shells coming from the tower at all.
(could not insert video so I post link onto YT)