I noticed that after updating to 17.12.1/17.12.2 (Adrenalin Edition) Rocket League started to have some strange artifacts for 1 second after hitting the "Play Online" button.
Edit: Same thing happens when hitting the "Options" and "Training" buttons.
I can't describe properly this strange issue , so i will attach a video where the issue is clearly visible.
RX 480 8GB
Windows 10 Pro 64bit (FCU)LG 23inch 5ms Freesync