The singer is said to have unfollowed a string of famous people of late -- including Dua Lipa, Zayn Malik, whom she was rumored to have been dating in March. Not just that ... but his baby mama, Gigi Hadid, and her sister, Bella, have also been scrubbed from Selena's IG "following" tab.

While it's unclear when Selena might've stopped following these folks, we know for certain they're not there now. And SG was following most (if not all) of them in the recent past.

So the question ... what gives??? And more importantly ... does this actually matter?!?

On its face -- coupled with Selena's history of social media feuds -- it would appear that it does ... especially on the Zayn front. Rumors swirled this past Spring about the two of them seeing each other, not to mention one alleged sighting where they were seen kissing at dinner.

While Selena has since made it clear she's "single" ... the Zayn rumor picked up steam for a while. Obviously, they're both pop stars -- and also seem to run in adjacent circles.

The Hadids and Selena have also palled around over the years -- and as for Dua, she was gushing over Selena just 6 or 7 months ago when asked about the prospect of collaborating with her ... ditto for Selena, BTW, who was quoted as being down in the same article.

Again, we have no idea why Selena unfollowed all of them ... but it points to some kind of falling out, which has been a thing lately for her. Look no further than Francia Raisa ... and let's not forget the whole "mean girls" thing with Hailey Bieber and Kylie Jenner.

Selena tends to mostly mind her business/do her thing ... but every now and then, she's roped into a social media controversy. Whether she's the one initiating it ... debatable.