What a disheartening experience! After completing Eriksson and Kalferi, I attempt the Federation Transport Attack. I targeted and disabled the three transports first, but as I'm fighting off the remaining ships I notice it says the objectives have failed. WTF? The transports are still disabled, but since I'm in combat I can't get their supplies. At this point I just stop fighting and wait to die, and watch them start up again and take a few minutes to warp out.
Then to rub it in, I leave the map and come back to find out that it won't reset unless I completely drop the mission and start offer. Double WTF?
What a waste of time! Seriously, this one takes the cake as the worst designed mission I've played yet in STO, and that says a lot (there are some real whoppers on the Fed side). It's one thing to fail the mission for some objective I guess I didn't understand correctly, but it's entirely another to have to replay everything I did successfully to this point.
Please reconsider this mission. The secondary objectives are fine, but not the primary objective.
Actually if you can try to fight off the ships attacking you first, but you have to kill them fast. If you go after the transports first then they will get their systems back online and fly away again before you can destroy their backup that warps in.
Also as a note you do not have to drop the mission entirely. Every zone resets after about ~15 min or so. If you failed and have to wait for it to reset, go do one of the other Sorties in Pi Canis, maybe two. By the time you are done the transport should be ready for another run! Also see if you can get help with the KDF PvE channel. There may be some people who won't help, even say it's totally soloable. And with some classes/ships, it is. But with others, it's not. Do not be afraid to ask for help in game.