Was on the verge of selling my phantom 3 4k took it out for one last flight after trying to down grade my firmware after i lost all distance and was amazed at one point it went 100 meters hight could have gone more and 160 meters distance could have gone some more but dont trust the drone with all the problems i have been having since the last update

To clarify, what kind of troubleshooting steps have you done thus far to try to resolve the issue?

i have been trying to down grade firmware which wasn,t working right then i switched the drone back on and it said aircraft needs updating even though it was still on the latest firmware. then it kept trying to update then update failed kept trying then after a while just recalerbrated the imu and the compass and just took it for one last flight before i sold it, and was shocked when it went to 160 meters distance away and 100 meters high i didn,t try take it any futher as i don't trust the drone after it would not go over 40 meters after the first time i updated will try it again today today and if its got some distance back will keep it