So i installed gt on New pc and while exploring New ores that are exposed are unknown for some time. I remember vividly that its caused by some option being on maybe?
Pretty sure that’s a vanilla issue where the packets with the tile data aren’t sent correctly, happens with quite a few mods. Relogging or simply breaking the pre should fix it.
Might be lack of a Block Update that causes it, relogging will fix it, or you can just mine it and you should get the correct Ore.
I do this to minimize the insane amount of Network Lag these Ores caused in GT5, so the Ores will only ever synchronize their Data when they are exposed and receive a Block Update, something that normal mining and explosives usually do do.
Do you have Optifine installed? If so, disable the “Lazy chunk loading” function