Device and Software information:
Device name - Nokia 6.1 Plus (Android One)
Model - TA 1116
OS version - 9.0 (Pie)
Poweramp version - v3 build 814 play (latest from play store)
Problem - Poweramp lock screen freezes. But track keeps playing. Even the lockscreen functions work. But no change in display is seen. I'm able to pull down and interact with notification panel also. I've included 2 screenshots here. In one, you can see the frozen lock screen. In another you can see the notification panel where you'll see another track playing than it is seen on the Poweramp lock screen. Because Poweramp lock screen is frozen and didn't update itself as needed.