Yeah. You don't reinforce their ignorance by saying they are correct. Best to either ignore it or state the correct answer while avoiding or acknowledging their stupid.

If it's a private conversation, attempt to correct once to test their ability to be corrected but ignore any future nonsense if they resist being corrected.

spouting absurdities as fact to make one's next statements sound reasonable is a common brainwashing tactic.

Yeah, it's how Ben Shapiro keeps "winning" debates with college students who aren't familiar enough with rhetorical fallacies:

"let's say that [absurdly incorrect but reasonable-sounding on the surface assumption]", followed by a conclusion that's inescapable when accepting that premise.