I'm using Dokucraft and was frustrated about what I'm doing wrong until turned my texturepack off.
Somehow ores are not hidden if resourcepack is active. But with vanilla it does hide the ores.
So.. this is probably a bug.

Oh, also I'm using CTM: https://minecraft.curseforge.com/projects/ctm?gameCategorySlug=mc-mods&projectID=267602

How does it look in game:
without textures:
https://cdn.discordapp.com/attachments/435392929847312392/448833131320180736/unknown.png

with textures:
https://cdn.discordapp.com/attachments/435392929847312392/448833353374760961/unknown.png

Hi there, sorry for the very late response. This should be fixed now. If it's not let me know and I will look into things a bit more.