Had the same thing in reverse on a 1997 Fabia. The needles light up, but the dials do not intermittently, except if you turn all the lights on manually.
I took the car in yesterday for several faults “Oil service required”, loss of phone connectivity and a noisy AC compressor.
They re-programmed the computer(s) for the first two and re-gassed the AC (although it was cooling fine) for the latter - I doubt if that will repair a noisy compressor - and I presumed the instrument panel fault was a computer glitch sorted by their laptop.
On the way home the dials went out again. I phoned and the receptionist said: ‘We didn’t see any problem’.
‘Did you drive the car?’
‘No’.
She said the only repair is a new instrument binnacle, so we’ll go with that, before the warranty expires in October.
Quite strange that the dials illuminate when the lights are on, but not always when they’re turned off. It’s not an electrical fault such as a bad connection or a dry joint, it’s an electronic fault down to those bloody computers!