AEG Lavamat Sticking

I have an AEG Lavamat Turbo 12830 which has a problem.

When a 95 degree wash cyle is selected it works perfectly but if a 40 degree cycle is selected it fills and washes then stops after approx 20 minutes.

The time remaining display reads 97 minutes and doesn’t move on.

I have checked the obvious, the pump is working, the fill valves and the heater element are all ok.

I suspected the NTC so tested this and althouh I don’t know what it should read it is 4.6k at room temp and approx 880 ohms when dipped in boiling water.

I’m baffled by the fact that it works fine on a 95 wash!

Any ideas gents?

Have I overlooked another NTC perhaps?

It’s a little crowded being a washer dryer and my eyesight isn’t what it was 20 years ago!!

Thanks in advance gents.