With Rubidium:

Without Rubidium:

I also had the same issue with magnesium.

Try to use with https://www.curseforge.com/minecraft/mc-mods/magnesium-extras

I have tested the mod in other packs and it seems to specifically be the pack that I was trying to use, FTB ocean block must have a mod conflicting and causing the graphical issues. Running it with vanilla + forge gives no issues, FTB university also works without any issues.

If someone else is facing this issue, I have a workaround for now. if you install this mod: https://www.curseforge.com/minecraft/mc-mods/calcium and combine it with magnesium (its not compatible with rubidium, even though it mentions the mod). This seems to resolve the missing textures issue.

Should be fixed on latest Rubidium's versions

U find another solution? I want to use oculus :c