When the Fabulous! video settings are chosen, the rendering becomes very glitchy and unusable. This could be related to MC-188669, but I have decided to open a new bug report because that one is marked as resolved, and this one has far worse effects.

I have disabled mods and the bug still occurs. Notice that in the big window, the block in the centre is regular clear glass, while the others around it are black stained glass that add another trasparent layer. Several other bug reports talk about a warning when switching graphic settings to fabulous, but I haven't met any with my system.

I have attached screenshots of the same spot, with rainy and clear weather, on fancy and fabulous video settings for comparison.

This bug has also been reported to Mesa, see #4026. There I have also uploaded a small video demonstrating the issue (it's 25MiB).