I think there is a bug that there is no vacuum chamber that can cold weld lithium steel at the cheaper recipe, available for crafting in version 0.19.6. The vacuum chamber research that should enable it unlocks an item called a vacuum flywheel housing or something, that is normally only unlocked after you get white science in endgame to create flywheel energy storages. It is also unlocked by the later research.

I attempted to go into the mods technology.lua and the recipe.lua to enable it and to change it back to the correct item being unlocked, but it did not seem to work. Is there a way I can fix this?

Fixed the issue, the configs were correct for Darkstar mod, it was a mod conflict with another mod called Enhanced Energy Storage that added another item in the game that was also called 'vacuum-chamber' as well. I was mistaken that that particular item was also apart of Darkstar Utilities, and once I noticed it was not actually apart of the mod, I removed the other mod to fix the issue.