Can confirm. The server I play on restarts every 4 hours. I had been searching for a tent for 6 days and finally found one. I sent it up at grid 066 012 making it very unlikely anyone would find it. After about an hour after setting up the tent the server restarted. When I rejoined it took me about 10 minutes to get back to where my tent was and it was gone. Amazingly I quickly found another tent and set this one up at grid 013 011 and stayed until the server restarted. When I rejoined after the server came back up this tent was gone as well.