Issue with destructible objects and targeting

In a mission I made, I have 3 destructible objects. One spawns at the beginning of the mission and can be targeted and destroyed. After the object is destroyed a boss spawns and needs to be killed for the second object to spawn. Same for the third.
The problem is after the first boss is killed (he and all 3 are extreme AVs by the way, I'm not sure if it matters or not.) the second object spawns, can be targeted but it can't be attacked. When I or someone running with me targets and tries to attack the target it registers as "Invalid Target". Unless I use the AE option to "kill target" the mission cannot continue.
I tried using different maps, similar objects and different objects. The second target remains invalid.

Thanks in advance for any help.

Did you set the second object to have guards? There is an issue with destructables where they can't be attacked until the guards are, so if you set the object to "single" it has no guards, and can't be destroyed at all.

I didnt set it to have any guards and i did try to aggro it but its still invalid

Well I attempted to redo this with enemy groups set up around the objects and I was able to target and attack the first and the second object this time. Normally it's just the first, but I still was not able to attack the third object even after killing off its enemy group.