I have a similar bug. When I type in chat I can see the text but it doesn't transmit when I hit Enter. Switching to another chat channel then switching back fixes this. It happens relatively frequently. Haven't found a solution yet. I'm assuming it's related to what you're experiencing.
Mortars do heavy AoE damage, the difficult part is getting your targets to stay clustered long enough for the projectile to fall back down, meaning someone who can tank (preferably melee) needs to hold aggro. Unfortunately STO is very noobish in that it allows DPS to also hold aggro which is useless especially when doing…