Don't know if this could fix your specific problems, but this is what I did and it fixed my issues :
After the update, I had errors on two units, on different TVs. I bought a 4k HDMI cable, but the problem persisted.
I found a website (below). I had to disable the device refresh rate and reboot, reset the display type to read my TV and not auto detect, and disconnect all cables from all devices, and reboot (specific instructions at the website).