Blurry images on the Mavic are usually caused by a hardware issue assuming if you have checked that auto focus is enabled and the lens is clean. If for whatever reason the gimbal ins't stabilizing correctly, double check to make sure the gimbal moves freely on the rubber bands connected to the mounting plate and make sure all of your gimbal axes are working. The gimbal PTZ cable breaking or coming partially unplugged can also prevent the auto focus from working. To double check this is not a software issue, test the focus in manual as well and see if it is working.