Defined Icon Changing

[c0nt4x]

Set up a number of custom button cards on my dashboard and one of them (External Doors, in the image) suddenly changed it's icon today, even though it's been fine for weeks up until now.

The code in the below image is exactly the same code as the 'Windows' button below, which has retained its defined icon. I've refreshed the dashboard, cleared cache and restarted HA but the random icon on the External Doors button is still appearing.