I just updated to Photoshop 22.4 and when I create a new document or open an existing document, regardless of file type, the entire canvas and everything outside of the canavas turns solid black, while docked. But once I float the project window(s), everything becomes visible.
I did notice that while docked and zooming in/out, that the file(s) would become visible for a split second during the zoom process.
See attached screenshots.
OS: 11.3.1 (20E241) MacBook Pro (Retina, 15-inch, Mid 2015)