Sporadic screen malfunction; applying pressure provides temporary fix

I own an iPhone 6 Plus.

For some months I have been experiencing an intermittent screen malfunction. At first I thought it was a one time occurrence, but over the past weeks it's started happening almost daily. I will provide a description of the malfunction thusly:

When waking the phone, the screen will be black, but visibly on. Occasionally, rather than black, the screen will be washed out and blurred. Usually, simply locking the phone and then waking it again will resolve the issue. If not, I've found that applying gentle pressure to the top right quadrant of the screen helps restore functionality. All other components and functions of the phone are operating normally, as is the screen when it is working.

Interesting note: When applying gentle pressure while the screen is working, it glitches and goes blank in the same manner as described in the preceding.

Is replacing the screen advisable, or is it something more benign like loose contacts?