[OnePlus Nord N10 5G Guides, News, & Discussion] BlindArtisan:
I was using the Pixel Experience Plus GSI for a few weeks and I thought it was working great. Everything was flawless except apparently it could not recieve phone calls.

My issue was that I could get IMS, it would show as registered, I could make outgoing phone calls, send SMS/MMS however I was having an issue with not recieving incomming calls on VoLTE. So basically I was not seeing any calls sent to me for weeks! I did a ton of troubleshooting. Installed Pixel Experience Plus fresh, then the regular Pixel Experience (non-plus), LineageOS 13, but all had the same issues with VoLTE. Eventually I gave up and went back to stock OOS 11.0.14 and everything was working fine. I tried things again today with much success after seeing something interesting on PE releases. Turns out a few updates ago some Qualcomm devices had issues with the default IMS apk and there is an alternative to install. So I reinstalled regular PE (non-plus) and it finally worked!!! I now receive calls on VoLTE and can send/receive SMS!

For anyone else experiencing the same issues, it might be possible that all you need to do to fix this issue is uninstall com.aroura.ims and install the new one. (https://treble.phh.me/stable/ims-caf-s.apk)

However, just in case this isn't the exact situation. Here are all the exact steps I took to fix it.

To fix VoLTE:

For context my device is a BE2029 and my carrier is Mint Mobile which is a US T-Mobile MVNO. The exact GSI I flashed was: PixelExperience_arm64-ab-13.0-20230713-UNOFFICIAL.img and I flashed from OOS 11.0.14.

Step 1) Start on a completely clean device reinstalling OOS through MSM tool.

Step 2) Update through OTA to OOS 11.0.14 (or current version)

Step 3) In android developer options, enable ADB and unlock the bootloader

Step 4) Reboot into fastbootd. While booted in android I executed in adb:

adb reboot fastboot

Step 5) Install the GSI

fastboot erase system_a
fastboot delete-logical-partition product_a
fastboot flash system (ENTER GSI YOU UNZIPPED HERE)
fastboot -w

Step 6) Go through android initial setup

Step 7) Instead of installing ims apk through the settings menu. Download and install the alternative ims-caf-s.apk from treble.phh.me (https://treble.phh.me/stable/ims-caf-s.apk)

Step 8) In PHH Treble Settings Options, enable "request IMS network" and "Force presence of 4G Calling", lastly "create IMS APN"

Step 9) Reboot

Step 10) In network & Internet settings > SIMs > Switch preferred network type from 3G to LTE. Ensure VoLTE is already enabled.

Step 11) At this point it was not working so I reinstalled ims-caf-s.apk (not sure if this was necessary maybe I just needed another reboot)

Step 12) Reboot yet again

Once android is finished booting you should have functioning incoming/outgoing calls on VoLTE!

To enable 5G:

For some reason the dial code to reach RadioInfo doesn't work with the default dialer app. So I used "Right Dialer" (https://play.google.com/store/apps/details?id=com.goodwy.dialer) to access the menu. You can delete it after you are done changing the network setting. Another option is to create a shortcut (I used Nova Launcher shortcut widget for this) Nova Widget > Activity > Phone Services > Phone Info (aka ".settings.RadioInfo")

Step 1) in "Right Dialer" dial the number *#*#4636#*#*

Step 2) go to phone information

Step 3) Set preferred network to "NR/LTE/TDSCDMA/GSM/WCDMA" (This was the default in OOS)

Step 4) reboot

Now you should have 5G with VoLTE working!

If this causes you any issues you can set it back to the default which is: "GSM/WCDMA/LTE (PRL)"

Note: It seems like it is getting changed to "NR/LTE/GSM/WCDMA" automatically, But I'm not having any issues yet.

Also shoutout to DSU-Sideloader (https://github.com/VegaBobo/DSU-Sideloader). It allowed me to boot to GSI and test functionality while allowing me to keep OOS as my main OS while I debugged. It's very straight forward to use and makes testing GSI simple before you commit to flashing it.

I was pulling my hair out for days, so I hope this helps someone enjoy android 13 GSI!

Edit:

I was missing some features from PE+ and decided to dirty flash over my PE install.

All I did there was reboot into fastbootd and ran command to flash the new system_a image

fastboot flash system (ENTER GSI YOU UNZIPPED HERE)

and then rebooted to recovery and wiped cache. It seems to have treated it as a system update and it is working fine with all my apps and settings persisted. I'll report back if there are any issues, but it seems this fix will work regardless of if you use the plus or non-plus version.