Sterling PRO CL intermittent immobilising

Have a 2004, 1.2 Fabia fitted with a Sterling PRO CL.

Two years ago fob went faulty so we put the alarm into 'valet mode' - i.e. turned off

In the last 10 days it has on 4 occasions immobilised the car. Never done it in last 2 years. What happens is car will not start ( turns over but no attempt to fire ). Take out keys, put keys back in, and it starts immediately - BUT the alarm light on the dash is now flasing for a few seconds then goes out. Then all is well and starts first time for the next dozen or so starts then same again.

I am worried it will one day be permanently immobilised.

QUESTIONS - Why is it doing this ( car battery is charged - green light on, no other issues ) ?

Can we remove the alarm ?

Can we disable the alarm ?

Thanks in advance

Edited 15 May, 201115 yr by langtone