Dilemna/Dilemma

Dilemma means "a situation in which a difficult choice has to be made between two or more alternatives, especially equally undesirable ones", but many people remember spelled it dilemna with an "n". Millions of people spell dilemma like dilemna. You would like to think millions of people would know how to spell a old english word. Some people theorize that we were in a dilemna universe than somehow got switched into a dilemma universe with a "m" almost like the Berenstain Bear conspiracy theory. Could this be a Mandela effect, or just cases of bad spelling?