I hate to break the news but Chrome does that too. I used similarweb to check my website that only I visited pretty much and it showed “other viewed websites” that only I visited. I tried some other small websites and saw websites such as “pornhub” in other visited websites. I didn’t have any extensions or anything. I’ve reached out to similarweb and was conveniently ignored.

Just assume that all sites you visit is a publicly available data.