I've got similar symptoms on my Android device, and have an ongoing case with VM Support. To help clarify if it is the same... (and I'll flag it if so)
Check your registered devices using "device management" on https://virgintvgo.virginmedia.com/en/settings/devicemanagement and make a note of the device name in question - capitalisation & spacing is crucial here.
Next time you load the app and it prompts for the device name, make no changes and simply proceed. After done, recheck the device management. Have there been any changes? If not, and the latest TV Go session is thus using the same slot as the previous device, this replicates the issue I've raised.
If so... can you confirm your device's Android SW version (usually found in the settings menu somewhere) and also copy & paste the output from TV Go > Settings > Diagnostics into this forum thread.