I am not sure what you are refering to. You absolutely can break Lorentz Invariance in string theory[1]. There is a reason why even some string theory researchers call it the theory of anything.

[1] https://inspirehep.net/literature/262241

That’s just piggybacking on a prediction of special relativity itself. If string theory predicted something novel that’s testable, that would be a lot more noteworthy.

Forgive my non specialist questions here, but doesn’t special relativity predict that special relativity is preserved at all scales?

as i know really nothing about the subject, could someone explain why parent was downvoted ? is it for the tone, or the content ? Because, i , having viewed the youtubers in question, had the same opinion about string theory.