I bought I BV4000 Pro on October 2018, and it worked quite well until some weeks ago. 

Now, sometimes the touch screen stop working, and I have no response when tapping in any point. To come back working, I have to lock the phone (pressing the power button) and unlock it again; sometimes it works immediately, other times I have to one about one minute before touch screen work again. Side buttons (power when volume) always works, so I see that the phone is not freezed.

I already tried a factory reset, but the issue continued, also without installing custom applications.

The issue is more annoying when using some games, that before worked well, now the game continue but screen often stop responding and I have to lock / unlock many times.

There is something I can try to mitigate the issue?

PS: I tried to post this to Feedback (https://store.blackview.hk/en/feedback) but I always get an error "[color=#dc3545][size=85]Valid content is required."[/size][/color]

thepisu wrote:

I bought I BV4000 Pro on October 2018, and it worked quite well until some weeks ago. 

Now, sometimes the touch screen stop working, and I have no response when tapping in any point. To come back working, I have to lock the phone (pressing the power button) and unlock it again; sometimes it works immediately, other times I have to one about one minute before touch screen work again. Side buttons (power when volume) always works, so I see that the phone is not freezed.

I already tried a factory reset, but the issue continued, also without installing custom applications.

The issue is more annoying when using some games, that before worked well, now the game continue but screen often stop responding and I have to lock / unlock many times.

There is something I can try to mitigate the issue?

PS: I tried to post this to Feedback (https://store.blackview.hk/en/feedback) but I always get an error "[color=#dc3545][size=85]Valid content is required."[/size][/color]

Hi.
Sorry, I have no idea to help you. 
I think you'd better contact our professional after-sales directly. 
After-sales email: support02@blackview.hk
They will help you directly by email.

By the way, you need to write all the required content when you submit your Feedback.