Yeah it seems like the health or timers for the two land-based objectives aren't quite working right at the moment. I just lost the city because in a perfect run after getting Dust Lance to the airfield I missed a single SPG and had to take the time to go around for a second gun pass, apparently that was enough to force Grendel into retreat after a dream run through the city, and I've had similar happen to Dust Lance down the middle.