Hello, I M Mazid Hasan Ronty, A Travel Film maker... recently i had puchase a brand new Mavic Mini 2 15 days ago.
Whenever my drone is in air it signal always lost .. is that DJi bugs fixed ? what would i do now??

Make sure you are using the latest DJI Fly App (v.1.9.0) and the drone's firmware is up to date.  Before you take off ensure you have a good GPS lock.  

I'm not seeing any issues on my used Mini 2 so hopefully you get the issue with your Mini 2 fixed soon.

Turn on the radar view in the bottom left corner and make sure the dot with the arrow is green,  this ensures that you are pointing the controller at the drone optimally.  

I never had a problem.