Had MOT Urgent Attention notice - 'Fuel filler cap solenoid temperamental, requires replacement filler door'. Anyone had that & what was the approx. cost?

If it is the solenoid that operates the locking mechanism then surely that should be the element that is replaced, not the filler door?

As to costs - anything from £10 upwards for the solenoid part plus fitting at about 5 minutes... Replacing the fuel filler flap actuator Skoda Octavia 3

10 out of 10 for your MOT person reporting that, it might just avoid you getting stranded while attempting to re-fuel.

It would be the MOT person checking the filler cap seal condition that ended up with that discovery.