Is this a known issue or something else? I followed a teammate in a war run last night and three times I hit the first three towers on the back island with execute and it took out the middle tower but left the front two I damaged. My AP is 4 million plus on the dragon used and these are mid level 50 towers. It should have easily destroyed them but it appeared a shield popped up right after I dropped the execute. Like when I destroyed the storm it triggered a shield and totally ignored the other towers. I watched it hit all three so it was not a miss.
The towers were dark flak and red mage on the outside with storm in the middle. Only a fire flak on the back.
I have flown this dragon hundreds of times and have yet to ever see this happen. Any help is appreciated. A ticket has been submitted.