Possible issue using Variables as Tiles on a Dashboard

While writing rules I create system variables (2 of them) and added them to a dashboard.
I deleted the variables, worked further on the rule and went back to the dashboard and the tiles were not the usual ? mark - but the layout said the squares were used.

Ultimately I could only clean it up by editing the JSON.

When you say system variables, you mean Hub Variables?

@sburke781 sorry. yes. Hub Variables. Not sure it matters but the first 2 I created where number vars.