When I open the journal, the textures for my health, hunger, xp bar and crosshair get liquid starlight textures.

HellFire, should I provide my computer specs if it is helpful?

i need to run some additional tests and stuffs (for which i didn't have time yet), but i don't think this is OS dependent. Modlist or pack name would be helpful i guess.

Well, there is one issue, I tried this mod solo with only optifine and latest forge, the bug still happened. I kind of have that feeling it has to do with the mod itself probably conflicting with optifine somehow and remember, the bug ONLY happens when I open the journal, no other render bug that I see, yet.

I'd suggest toggling off some of Optifine's features to see if you can narrow it down further. For instance I know the "Performance > Fast Render" option can cause some mod conflicts.

I can confirm that turning off Performance > Fast Render fixed the issue for me. Optifine's own tool tip warns it sometimes causes graphics glitches

i think it is fast render