AutoCAD .NET :: Add Block When Other Drawings Are Open

I'm trying to add a block with an attribute to a drawing. The command works if there is only one drawing open, but when there are other open drawings then the block doesn't appear. Strangely if I select the block in the block editor and then close the block editor the block suddenly appears. Do you know what is causing the block to not appear when other drawings are open?

I included the code below. "s1" works but "s2" has the strange behavior of the block not being visible.

[CommandMethod("s1")]
public void AddBlockWithAttributeToDestination_WithNoOtherDrawingsOpen() {
    var attributeValue = "1234";
    var destination = Application.DocumentManager.MdiActiveDocument;
    using (var transaction = destination.TransactionManager.StartTransaction()) {
        addBlock(transaction, destination.Database, attributeValue);
        transaction.Commit();

[code]....