Music Player and Audio Recording Crashes Randomly

My **Music Player** can't play more than **5mins & 10sec** after you stopped using the screen, same with my **Audio Recorder** and after the short records it stores as **.3gpp.tmp** which can't play on android because of the (.tmp). I was told that **Nova Launcher** app can help but I can't get the full details. **More Details.** Music Crashes on **Boom player, Google Play music, VLC & Music player by Mobile_V5**. Yes I withdrew from Battery Optimization and it didn't work. Model: **Itel A51** Version: **6.0**