Lenovo K8 Plus music key not working

Lenovo K8 Plus music key is not working at all.

In System UI Tuner (activated this in Settings) also, options like long press music key to perform a task like flash light, music play/pause etc. are not working.

The music key is just not working!

Model- Lenovo K8 Plus (XT1902-2)

Build No.- NMC26.74-31