An upgrade to 23.3 causes creates a green playback screen when "Metal" is selected. When "Software" is selected the problem goes away. Media Encoder will not encode files when "Metal" is selected. When "Software is selected the problem goes away. I rolled back to v23.2 and "Metal" behaves as it should.
2019 Mac Pro 16-Core
192 GB Ram
2x Dual Radeon Pro Vega II GPU (effectively 4 GPUs total)
Apple Afterburner Card