Is this a red flag? Help me girls

My boyfriend (23) has been a really good partner overall—he’s consistent, caring, and I haven’t seen any signs of him hiding messages or talking to other girls in a suspicious way. He’s also very transparent with his phone. If we’re lying in bed and he’s on it or showing me something, I can see the whole screen—his Messenger, Instagram, everything—and he never acts like he’s trying to hide anything.

Recently though, I noticed in his Facebook activity log and search history that he sometimes searches for girls he knows from school. One of them is someone he used to talk to before we met. I didn’t see any messages or interactions with them, just the searches themselves. It made me overthink a bit and wonder if this means he’s still curious or interested in them, even though his actions toward me haven’t changed at all. I’m trying to be rational about it, but I’m not sure if I’m overthinking or if this is something people would consider a small red flag or even micro-cheating. Has anyone experienced something similar, and how did you interpret it?