One of my device was not showing up properly and lost its connection with SmartThings, but after I’ve fixed the issue the original tile became a place holder and it no longer can be removed.
I can try to recreate the dashboard but wanted to see if there is a better solution to this. Copying the dashboard does not help as the place holder is still not removable.
I ended up just recreating the dashboard - took only a few mins 
Though it would be great if these phantom placeholder could be removed.
Thanks for report and sorry for the inconvenience. There should be an X right where the arrow is pointing to. It’s probably defaulting to white and not using the foreground color from your style. We’ll take a look at tweaking that so it respects the style and is more visible.
