I have 3 adult children. My DS is 23 and lives and works in a town 10 miles away. We all get on and enjoy being together. We have a family WhatsApp, and everyone usually messages every couple of days about pets, Wordle, all sorts of stuff. DP is away doing something quite exciting at the moment and he's posted a few videos. All perfectly usual. Except that DS came back from holiday 2 weeks ago, and bar a "we're home!"message hasn't posted since. It's the longest time he's not posted ever. I've sent a couple of messages just to him about practical things-no reply. I know this is perfectly normal for lots of people-but it's not for us. Obviously I'm not going to ask his siblings whether they've heard from him. What would you do?