I feel similar with phantoms. I think this has to do with cannon s that are non -centered on a unit's model. Siren has this super strange rear turret, phantom projectile starts from in front of it and to the side. I know that there are cases where hermits and thugs will friendly fire half their shots if they are not moving because the cannons alternate firing, and they are both off center. I believe someone made a post about 4 months ago about the same with Cerberus plasma artillery friendly firing like such as well.
Other off topic cases include Grizly having trouble firing on surface units because it's AI will not float it, but it's AI will also not move it closer because it is "in range." I would assume the same is for buoy and archer. another off topic case is in rare cases a unit will not move to fire on a directly targeted unit if it has already stoped moving and an obstruction appears. Take case: ronin is firing on llt, solar collector in front of it dies, ronin will not move or fire due to obstruction. There also exists a report on GitHub about units giving up on their direct attack orders.
