Recently had a customer trying to connect and sync their onedrive which would fail with the error 0x8004de40

After investigation , it looks like the customer had a Telstra Router with Backup 4g , and the NBN had been cut so it had been running on 4g for a month

I’ve had this before with Onedrive where the App just doesn’t work over 4g and the customer has to use the web version , as soon as NBN was restored it worked fine!