DIAGNOSIS This is an HDMI handshake failure, often related to the VRR (Variable Refresh Rate) or 4K/120Hz signal format. The TV's HDMI port is not correctly synchronizing with the console's output signal after sleep or a game change.
FIX On the PS5, go to Settings > Screen and Video > Video Output. Set 4K Video Transfer Rate to -1. Disable VRR. On the TV, press the Input button on the remote, highlight the PS5's HDMI port, press the Up arrow, and select Signal Format. Change it from Enhanced Format (VRR) to Enhanced Format (Dolby Vision) or just Enhanced Format. Restart both devices.
IF THAT DIDN'T WORK The issue may be with the TV's Bravia Core or Auto Calibration features interfering. Go to Settings > Channels & Inputs > External Inputs > Bravia Sync settings. Set Auto Power Off and Auto TV On to Off. Then go to Settings > Display & Sound > Picture > Adjustments. Set Auto Picture Mode to Off.
HEADS UP Always use the included Sony HDMI cable or a certified Ultra High Speed HDMI cable. For this model, HDMI ports 3 and 4 are the full-bandwidth 4K/120Hz ports. If problems persist on one port, try the other.