Just get a new job, interviewing isn't hard to get an offer of the same, or better comp.
Most H1B I've worked with would be dead-in-the-water in any FANG, or FANG-adjacent interview that doesn't stress rote-memorized garbage.
Also, their coding fluency will be low, so they'll just know how to solve the algo, but aren't anything close to let's say, knowing the internals you would need to know to be a standard library/language designer. They only know enough to solve the question.
You will notice the same during systems design interviews. A senior/principal might go "put cache here, redis, blah blah oci xyz". Nothing deeper, as to how it works, why enforcing data consistency can be slow, and anything else that shows that you actually considered a piece of technology for use in a design, or used it.
Good luck. Lots of "innovation" happening for EB-1A.