For a 2021 XC60 Recharge T8, finding that the Volvo On Call display gauge under fuel range for electric is unreliable. This is not the case with the fuel gauge for gasoline.

Is anyone else experiencing this and is there a fix? Is this a software issue, a vehicle cellular connectivity issue, something else?

 

since you are under a new car warranty, why not have the dealer use their tools to validate the accuracy of the gauge? Additionally they can check for any applicable software updates. Personally I'd doubt it is a cellular connectivity issue - that would not alter the data - you'd either be able to connect and send data or not.