He was subjected to house arrest for advocating for a "new" idea. We now accept heliocentrism as the correct answer. It's not terribly important to me if it was, in fact, his idea...etc. etc. He's the best known example of "scientist says something we now currently accept as scientific fact -- and there is hell to pay for him during his lifetime."

W.r.t. Semmelweis, I don't know how this played out,

He was a physician in charge of two clinics who had studies backing up his "crazy" idea that physicians should properly sterilize their hands before delivering babies if they wanted to reduce mortality rates. He was essentially driven crazy, thrown in an insane asylum and beaten to death by the guards in short order.

I view it in simpler terms as "He was effectively murdered." because although he had studies, he had no explanation for how and why, so it was rejected out of hand.

This was maybe two decades or so before we accepted germ theory and modern sterilization techniques for surgeries and so on.

https://en.wikipedia.org/wiki/Ignaz_Semmelweis