Logs: https://gist.github.com/Nightenom/eb3c16ddbc3d1b8c2803c1ee78b0c318

Desc: after changing shaders latest.log gets spammed with error message, till first shader change everything is fine, after that you have to restart the game to make do blocks working again

No clue, Optifine is not supported anyway, i tried to fix this without it being in my dev env but was not able to, closing since this is out of scope.