Recently bought a oneplus 7pro online from oneplus store in the US. All phones sold by them are unlocked. (not so if u buy from tmo)
Thought I was being clever and making my life easier - good specs, cheaper than samsung, etc, unlocked, dual sim so I could leave my US sim and insert local sim. Well it didn't quite work that way. No problem in the US (well except for some issues which were mostly solved by putting the sim in slot 1 and some that weren't solved at all like audio notices not working, etc.)
However, when I got to Thailand and topped up my AIS for data (one that I had used before in my samsung) got a strong 4g signal but NO data transfer at all. This puzzled me since AIS sells oneplus phones and the specs look the same (bands, etc) 3 hours of trouble shooting in 2 AIS shops led to no solution (my sim worked in salesman's phone and his sim did not work in my phone).
Oneplus support has been hopeless. I think the problem is that oneplus does not have an agreement with the Thai carriers (but that doesn't make sense since the ones sold in Thailand work) - or maybe there is something like a band missing from my phone???? AFAICS, though the specs listed for the phone sold in Thailand look basically the same as the one I bought.
Anyway a caution for anyone considering this phone to use in these circumstances
