One of the common issues with HTC One M8 is that the device seems to be on the roaming mode. This may lead to the fear of high roaming bills, even through the phone is being used from the same region of service. The roaming bug is related to a software issue, and HTC has maintained that uses with this problem (of seeing the roaming signal, even though it is not being used) are not charged for roaming services. Here is the workaround to solve the issue –
Here is the solution –
Check if the HTC One M8 is up to date. You can check if the firmware is the latest one by going to Settings – Software Updates – Check Now