PUMPKIN CAR STEREO SUPPORT CENTER

I just bought "Pumpkin 2 Din 7'' Android 8.0 Universal Car Radio No DVD Player GPS Navigation 4GB RAM Car Stereo FM Rds Wifi 4G DAB+ Headunit" from aliexpress and I am using it for 5-7 days . I installed it on my nissan quashquai 2010.
Order id:90777166260063 aliexpress
I allready updated to last firmware
Problems :
1. WiFi works just 5-10 minutes and than I'll looses signal and it stops . If I try to reconnect it doesn't find any network although I have my phone hotspot in the car
2. When multitasking ( chrome + GPS + Google play for example) the screen just turn off without possibility of turning back on . It needs a forced restart to work again .

Do you have any ideeas of what I can do to solve these problems ?

This article has suggested to me many new ideas. I will embark on doing it. Hope you can continue to contribute your talents in this area. Thank you.