I shot this video until I reached the bridge with the antenna folded down, I didn't notice that until I got msg of week transmission signal . After I put them up I get the signal back , than I lost it again I had to do U turn & star heading it back to get the signal back ,  I wasn't sure if that was because I didn't put the antenna up from start point ? Or what ?  . & What's the best position to point the antennas to get strong signal ?

The antennas work best when pointed away from the drone.
The signal is weakest if you point the tip at the drone.
First part of this video explains the antenna types used on the Mavic.
Not my video. Saw it years ago when i first got in to FPV.