It was with enthusiasm that I decided to switch to Google Fi. It turned into a nightmare, with my iPhone being hosed no matter what SIM I subsequently used.
I installed the Google Fi SIM that arrived in the mail, and it worked. (Although poorly enough that I am abandoning Google Fi…more on that in another post.)
But when I switched my SIM back to Verizon I could no longer send SMS messages to anybody. No matter what SIM I used, I could no longer send SMS messages.
I called Apple and their support staff suggested that I reset all network settings. Begrudgingly, I did that. Not only did this fail to fix the problem, but it wiped out all of my VPN settings and WiFi passwords, including from my desktop and laptop (since Apple cross-syncs them between devices.) Finally, Apple was out of ideas as they indicated that it seemed my phone may have been “permanently damaged” by the Google Fi SIM.
Next I contacted my local Verizon store. They replaced my Verizon SIM (twice) and de-activated and re-activated my line. They deactivated and re-activated iMessage and SMS messaging. And, again, they “Reset all Network Settings” (once again wiping out all VPN and WiFi settings.) Finally, they offered to sell me a new iPhone and suggested I could trade in my now broken model.
As a last ditch effort I re-installed the Google Fi SIM, and SMS messaging started working (but only while the Google SIM was installed.)
And then the answer hit me: When installing the Google Fi SIM it is necessary to set some APN settings. But the menu that accesses the APN settings is only visible when the Google Fi SIM is installed. When other SIMs are installed the APN setting menu is not visible. So, I reset the APN settings manually to factory defaults, and then removed the Google Fi SIM. Installing the Verizon (or any other) SIM now allowed SMS messages to be sent. Problem fixed!
The solution is this: Before you remove the Google Fi SIM you absolutely MUST manually reset your APN settings to factory default values. Once the Google Fi SIM is removed you cannot do this, because the APN menu is no longer available to access.
I’m going to claim this is actually an Apple bug. The reason is that Apple is clearly still using the manual APN settings, even when the APN settings are no longer accessible. Removing a SIM that doesn’t need APN settings should also ignore the manual settings.
It’s actually a double-bug on Apple’s part. Doing a “Reset All Network Settings” should reset any manually set APN settings, including ones that are hidden. But it doesn’t; resetting ALL network settings doesn’t reset all network settings, only the visible ones.
Years ago I would have reported this double-bug to Apple. But as far as I can tell, there is no longer any effective way of doing this, and there is little evidence Apple cares about bugs. So doing so is most likely just a waste off my time. (In the era of Steve Jobs Apple pounced on every bog and promptly fixed them…those days are literally dead.)