iPhone 6 touchscreen problem

Hello Together,

I have an iPhone 6 16 GB after a little drop I get some troubles with the responsibility witch the touchscreen, it drops out during use sometimes came back , but sometimes I need to make first a hard reset. After a reset it works fine but after using a while it stucks working again. I already make recovery of the iPhone but no fix , I think is a hardware defect, but what can it be?
The display has no damage everything is fine, when it works without any trouble , but it drop out working himself. In the last time very often.
Thanks for you’re feedbacks in advance.