Have a GSM Google Nexus 5X. Data roaming is turned on in the phone. International Data roaming is turned on in my account settings. But while signal strength is very good and I can make voice calls, I have not been able to get data going. Ting Help says there is nothing they can do about this, unlike if I was in the USA. Strangely enough, I was here 2 months ago in the same location and data roaming was fine.
International data roaming in Bangalore India