Hello,
Same problem, currently in RB 7.0.1 and updated from 7.0
Ok, there are differences between some files contained in "\share_init\shaders.tar.xz" and the files presents in "\share\shaders". In the image example you can view the difference:
21c74bcb-258c-4c42-b2b1-305225e08000-image.png
Solution that worked for me: Just extract the files from the archive "shaders.tar.xz" and overwrite the files in folder \share\shaders\
Raspberry pi 4b