The cleaning guyI had similar display problem last year with an LG G4 that had one similar bar in the middle of the display. After the service tech (well, the cleaning guy who answered the phone at Verizon) had me do all the software troubleshooting and the factory data reset, my phone was replaced.
You said you bought your phone in June. I think the manufacturer's warranty is just one year, so I'd get warranty claim going soon.