I know someone who had this problem and said that he dropped it before this green line appear. He is out of warranty. The unauthorized technician said that the cable connecting to motherboard and display got damaged and needs replacement somehow his Rog phone 5s got fixed now. He said it has been 6 months and it is working fine . But as usual, the authorized service center said to him it needs motherboard replacement. Even I am having second opinions with my RoG phone 5 that just completely died weeks ago while using bypass charging and playing demanding game app . Authorized service center says Motherboard replacement while the non authorize repair center says it got short circuit since it heats up around motherboard area while it is plug with original charger and needs to replace IC component and the battery.