Check the Icing indicator
dont trust it 100%
Keep checking the lighted icing indicator, in icing its a the best visual indication!
“The A320 detector vibrates at a rest frequency of 40.000 Hz.
A shift of 133 Hz represents an ice thickness on the probe of approximately 0.020 inch and lead to the ice signal which remains active for 60 seconds.
For the A320Fam a ice "detector" is only an option.
Normally there is only a lighted icing indicator between the windshields.”