Hi there,   I purchased a Samsung S10e from Optus 3 years ago through a phone plan.   When the contract/plan ended, I purchased a TPG SIM only plan. TPG and OPTUS themselved worked in the background to make the switch happen.    Recently I got a new phone that I purchased outright. I moved the TPG sim card to the new phone and everything works just fine. Then, I sent the old phone (Samsung S10e) to Indonesia. When my brother inserted an Indonesian SIM card into the phone, he got a message that says 'Not registered on network'. The phone itself can be used; the problem is with the network.   My question is, is this something that I have do deal with with OPTUS or TPG? And can someone please confirm for me that a phone lock is different from a network/SIM lock?   Many thanks! ... View more