[Google Pixel 6 Pro] roirraW "edor" ehT:
You're welcome. I wouldn't be able to provide the knowledge that I have without the excellent education I receive regularly on XDA from users such as @Lughnasadh and others. I'm always learning something new.

Have you tried a factory reset?

I understand the bootloader isn't unlocked, but if you are able to unlock it, you could do so (which will force a factory reset on your device, so have anything you want to keep backed up off the phone).

As far as flashing both slots, just FYI, there's no need to flash the full update to both slots - only the Android 13 bootloader, but I think flashing that manually to both slots would require you to have the bootloader unlocked (as well as some other steps after unlocking the bootloader like enabling USB Debugging and installing the Windows Google USB Driver while the phone is in bootloader mode, and of course, always use the latest official SDK Platform Tools. Anyone, please correct me if I'm wrong about needing to unlock the bootloader to manually flash the bootloader to both slots.

*If* you unlock the bootloader, then I would suggest using

Official Google Android Flash Tool

(OEM Unlocking needs to be toggled on - you may not have to manually unlock the bootloader - the "site" will do that on its own). This official flash site has solved all sorts of unusual problems that users have had in this section, including for me. Problems that manually flashing the (full) firmware zip didn't solve, which is indeed strange, but it's a fact due to just how many users have reported their issues solved with the site.

Now, I wouldn't unlock the bootloader just for the ability to flash the bootloader to both slots. You should automatically receive the September OTA, although of course, you can manually flash OTAs. I would only unlock the bootloader if you plan on rooting the phone, or if you just want to have more options available if something goes wrong on the phone.

If you're comfortable unlocking the bootloader, then, by all means, do so, but just be aware, that unlocking the bootloader can also have the unintended effect that you can accidentally flash the wrong thing and brick your device as well.

Flashing anything to both slots will not solve your Wi-Fi problem. I know that taking the automatic September OTA will update the slot that you're not currently on, and then reboot into it, so at that point, there is absolutely no need to update anything to both slots, as it's only while you have the old Android 12 bootloader on the inactive slot, and the Android 13 bootloader on the active slot (and have booted into Android 13 at least once) that there is the possibility that if the phone has trouble booting into Android 13, that it will attempt to revert to the old slot, which will cause a permanent brick that only Google can physically repair. The main symptom of this hard brick is a black screen, although just in general - having a black screen doesn't mean you've experienced this particular hard brick situation.

I never had any Wi-Fi problems in the last 10 months on my Pixel 6 Pro, so I don't know what will solve it for you. Does it have problems on Wi-Fi everywhere, or just at home?