AI cargo ships, light cruisers, destroyers, and heavy cruisers cannot be locked at a distance of 10 km or even closer. Most of the time, only one target can be locked.
besides that they shooting over their effective range and this is a bug, that devs forget to fix when they fixed AB aiming bugs recently
https://community.gaijin.net/issues/p/warthunder/i/MZEl4Vg1GL25