Any referee should have realised Law 11 refers to offside.Correct. I relied on your numbering. I hadn't actually googled it to confirm your numbering was right.
My understanding comes from actually having been a ref. Reffing games, and reading a Referee's manual. Granted, I haven't done any actual refereeing since before the pandemic. I am quite intuitively familiar with the laws and their interpretations. Which goes above and beyond just the statement of laws that you have up there. to include all other aspects of refereeing including rules, definitions, interpretation, game management, communication etc
But that's neither here nor there. It was wrong of me to trust your writing when a basic Google search to ascertain the right rule # would have sufficed. I' promise to do better next time.
My spheres of active officiating in "soccer" include the FA Cup, Football League, Northern Premier League, and the Central League.
I suspect that your referee instructors might themselves need further instruction.