Just keep trying JLR support then maybe its not your phone  2018 SE SDV8 4.4 Byron Blue

Crikey, you're easily persuaded

My remote app has decided the car is unlocked (It isn’t, I checked!) and won’t update / refresh when pulled down. Any ideas why? My battery is probably getting a bit long in the tooth, only showing 12.47 Volts and 74% state of charge, might that be causing the issue?

The 2 sunshine symbols indicate its trying to update phone app with your car status and failing to do so.
Try deleting and re-installing the app, is the subscription valid? go to web site and check.

if still the same Contact Incontrol people http://www.landrover.com/incontrol lol maybe customer service can direct you to the Incontrol people.

If you have an OBD2 do a DTC scan, I once had issue where remote thought the car was at the last service station I had visited and after DTC check there was a TCU fault which when cleared brought the location status back to normal, maybe it will help? 2018 SE SDV8 4.4 Byron Blue