We can use either of the adverbs however or nevertheless to indicate that the second point we wish to make contrasts with the first point. The difference is one of formality: nevertheless is bit more formal and emphatic than however.

I think they are pretty much the same, but “however” is a bit less formal and is used more often. See: https://answers.scottsenglish.com/discussion/10/explanation-however-vs-nevertheless Or: https://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv206.shtml