Happens quite frequently if you know where to look. They’re called “footshots” and are typically done from Vandenberg AFB into small remote islands to test internal components and electrical equipment of Reentry Vehicle style warheads. No physics/nuclear payload obviously.
I've been around a long time and I don't know when anyone ever paid any attention to these tests. The only reason I do is that I was on a missile equipped submarine.
There’s nothing really special to read into this given their regularity over the last few decades. You can see past ones listed on the Vandenberg AFB web site every year or two. It was more interesting that they delayed one due to the tensions with China a month or so ago, likely to avoid sending the wrong message.
