I tried the following and PUBG sound and overall headset sound is loud and clear for me|
Settings> Additional settings > headset > Mi sound enhancer and General headphones selected.
I also got a PUBG update...so not sure what the reason is...but i have very good sound from headphones now.
In order to fulfill the basic functions of our service, the user hereby agrees to allow Xiaomi to collect, process and use personal information which shall include but not be limited to written threads, pictures, comments, replies in the Mi Community, and relevant data types listed in Xiaomi's Private Policy. By selecting "Agree", you agree to Xiaomi's Private Policy and Content Policy .