Grope has the same meaning in American English, and used in that context could be fine ("grope around").

But I have never heard "groper" used for anything other than some engaging in sexual assault. The benign sense of "grope around" isn't a sufficient part of an identity to ever use the word "groper", while he sexual assault sense is, so "groper" implies the sexual assault meaning.

It's entirely likely that the original author of this phrasing was thinking about it in the benign sense, but didn't realize that the phrasing would make many readers interpret it in the sexual assault sense.