[Google Pixel Questions & Answers] Master Cylinder:
Starting about 8 weeks ago after owning the phone for more than 2 years, I started missing calls and texts that would only show up after a reboot. People also told me that when they called sometimes, there was no connection and no way to leave a voicemail.

People are usually still 7-digit dialing and texting here. I live in New Mexico and most of the the state is 505 since forever, so people here never think of 10 digit dialing unless it's out of state. After about 5 hours with 2 different Fi tech chats and some research and experimentation, I figured out that when my phone was switching to Sprint, it was getting a "shadow" number with a 214 area code, which is Dallas. When on TMO everything works fine but if it switched to Sprint, I would miss a lot of stuff, and with 7 digit dialing be calling Texas, or sometimes getting notice of an invalid number, and sometimes I couldn't connect to the network at all.

From a reddit thread https://www.reddit.com/r/ProjectFi/c...ile_on_sprint/ that has some other interesting info which seems plausible:

"I think it's because of your Sprint Shadow Number; on Fi, Sprint and US Cellular assign an "invisible" internal number to you so that the towers are able to know who you are, as well as routing your calls properly, among other things. When you dial a 7 digit number, the area code of your phone number is appended to the beginning of the number, that's why they work fine when you dial a local number. However the Sprint number is often times not a local number, and the area code usually differs greatly from that of your actual Fi number, so the 7 digit number is now trying to call somewhere else, probably a number that is invalid."

The codes used to monitor and force a switch to a specific carrier might be google-able, though I haven't found them just yet (I got them from the chat) but using an app called Signal Spy or FiSwitch one can easily monitor and force a switch to a specific carrier without having to memorize and enter the codes, though the codes are available through those apps. Also reading the mountain of reviews you'll see how many people are having problems with Fi carrier switching choices.

I turned off my network reporting in the Fi app and have the Signal Spy app running and so far haven't had any switches to Sprint, though I don't know if that has anything to do with it. I don't know why this just started happening and they couldn't or wouldn't explain it. They just told me, from Bangalore or wherever, to just 10 digit dial, but that doesn't help when people frequently 7-digit dial or text me here. It's New Mexico!

What I've been looking for is a code to lock it on a carrier but haven't figured it out yet, though there to be a possibility here on this page which has a pretty exhaustive list of the codes but none of the codes used through my chat with the Fi tech to reveal connected carrier, change to T-Mobile or Sprint, or repair the network are on any of the lists I've seen so far! They are in those previously mentioned apps, though:

https://mobilespecs.net/phone/codes/...gle_Pixel.html

After 2 years of flawless, stress-free usage and glad to be away from the gouging and control of the major carriers, my Fi bubble has burst. Anybody else having Fi heartburn?