I purchased a refurbished Moto G5 Plus XT1687.
I confirmed in two ways that it should be usable with Republic Wireless (through the web procedure and through downloading the RW app which prompted me to buy a sim card)
Inserted the Sim Card, but it was not recognized after multiple reboots, hard resets, and a factory reset.
RW Support has just told me that the problem is that the phone is stuck on Build number NPN25.137-33 and that it would need to update to the current build number NPNS25.137-93-10. Alas, Settings -> System Updates says that my device’s software is up to date, so, apparently the phone was rooted or modified in some way before I purchased it.
If someone here knows some magic that would let me get my system software updated, I’d be most grateful.
I (and I imagine other prospective users) would also be grateful if the “Bring your own phone” procedure was revised to, minimally, notify people of this potential x-factor (e.g. “In addition to having model XT1687, you also need to be on the current build, which may not be possible if the phone was modified/rooted.”) and, preferably, advise what Build Number would be required.
I.e. RW is limited in what it can do in step 4, but the documentation for step 2 could be much more helpful than it is.