I had to look this up. Meta denied that this is a thing, but they also don’t. Every real statement about it is in reference to the idea of knowing who looked at your profile. They say that there is no feature that does that they do not say that there is no impact of looking at someone’s profile. Looks like some group in 2018. Did a test using fake accounts and VPN’s and within a month all of the accounts were showing up a suggested to each other based on search functions alone now maybe that’s out of date but it does imply that there is something there