Steering wheel radio controls

[Seat survivor]

The steering wheel radio controls stopped working the other day. Not a disaster, but it niggles not having them working. Has anyone had the same problem and found the fix?
The horn still works and I have checked the plugs on radio rear and the two circuit boards and wiring in the steering wheel. Could it be a faulty Airbag Clock Spring Squib?
Keep safe, James

 

[MW05]

Other than checking for a blown fuse, I wouldn't have a clue. I bought my Ibiza with a hole in the dash so fitted a radio from my shed. It works but none of the buttons on the wheel have ever worked.