I (F 20) have a close friend (M 21) that hasn't been responding to any of my texts for about three weeks. The last time I saw him was at a party at a mutual friend's house three weeks ago. I don't recall anything out of the ordinary happening at the party that would explain why he's not responding. Usually, he's not great at responding but usually responds eventually. I would estimate that only 10% of my texts went unanswered. But I've texted him 10 times in the past three weeks with no response. I texted him pretty mundane things about sports, or sent him memes, in line with usual conversation that we have. I also texted him to make plans twice, and even called him but he didn't pick up.
About two weeks ago, I texted a mutual friend of ours to ask if she'd heard from him since it was weird he hadn't responded to me. She was actually with him at the time and I asked her to ask him if he was mad at me or something, and he apparently said that he wasn't, that he loves me and is just bad at responding. But he still hasn't responded since then.
I haven't ran into him in person since the party, but it's possible I will because we go to the same university and have some of the same friends. But there's no routine event I'll see him at or anything like that. However, I'll most likely run into him within the next couple weeks.
How can I ask him if there's a reason why he's ignoring me? And if I do, should I try it over text or just wait until I see him in person?