2021 Tucson MHEV ISG not working

[tucsonjohn]

Hi
I purchased my 2021 Tuscan Ultimate MHEV last month and have added some 800 miles to its previous 6800 miles.
In the first week the ISG worked as did 'sailing' on occasion (I was using the aircon, btw). Since then neither has worked once. Is this down to the recent warm weather?
I would have expected the benefits of a MHEV, with its additional battery, to be available in a wider range of conditions compared to a standard car.
I'd be interested to hear your experience of ISG, particularly for the MHEV Tuscon.
Thanks

[tucsonjohn]

Apologies