Yes and no.
"Iser mountains", even if "correct" (ok, the Germans call it Isergebirge) is not used anywhere.
I'll leave it in the page's text, along with explaining its origin, but change only the title of the area page.
You're not the one who mispells the most places, far from that. Just look at the High Tatras area and count the number of Slovak peaks spelled in Polish...