When someone repeats an argument that has been proven false /badly argued many times before, but keeps repeating it in hopes of drowning out opposition or derailing a thread. Yet not disruptive enough to get banned on forums, as it wraps itself in non-hostile, nicely written sentences.
How exactly do moderators deal with this kind of behaviour?
Gish galloping I think? If they’re repeatedly asking you to prove the argument false that falls under sealioning too. It’s also a very common tactic for some trolls to pretend to be civil in order to bypass suspicion.