"Daily occurrence"? That certainly hasn't been my experience. I've done two software updates over the year I've owned my '23 Limited and both have gone smoothly, using my home wifi. I have the "auto update" feature turned off (as I do on every single device in my life that has that option), so that I know I'm in a situation where I can monitor the upgrade and make sure everything is correct and powered off afterward.

The dealer who did your update and replaced your battery -- was it the dealer from whom you bought the car? Seems like WAY too high a price to charge for the software update. Assuming you bought the car there and had been using them for service, I actually can't believe they wouldn't do it for free as a courtesy. And did they test the battery before replacing it? I suspect that if it went flat due to the radio being left on overnight, then it would have responded just fine to a proper charge. Smells pretty fishy. Good luck, and . . . maybe seek out a new dealer.

 

Software updates do require a fair amount of active power, and can be draining. Especially to an older battery. The book says the vehicle should be running or connected to a maintainer/charger if off to ensure a successful download and installation. It's likely that you are writing to flash memory or similar re-writeable technology, and a higher than normal voltage is typically required to do that without error. That said, it's unlikely that most owners would know the recommended procedure for OTA updates if the screen doesn't advise you on the steps to take before responding yes, and walking away.

AAA jumped you, and the battery seemed to recover (although without load testing we don't know how completely). Given the Battery Settlement terms, it seems that you might have qualified for assistance here if the battery was compromised.

My suggestion would be to call 1-800-SUBARU3 and open a case. Be nice, polite, etc., but ask for a review and help with the cost of this misadventure.

 

Sometimes software upgrades don't go through the first time, especially if the Wi-Fi connection is weak and data packets were lost. The radio will check the file before install and will abort the install process if the file is not 100% perfect.

Software updates have been a usual daily occurrence

This is not normal. I get on average one update a year. It was most likely trying to tell you that a software update was available for download and install. It will do that every time you start the car if you have the "automatically check for updates" selected in your menu... and are out of date.. you can switch this off if you like.

and turned off the engine, I got a message on screen asking if I want to start software upgrade. I replied yes, and stepped out of my car

What happened there was It began to upgrade your firmware but then the radio shut off when you exited the vehicle stopping at mid upgrade. The radio wasn't able to complete its task before the power got pulled. Something was most likely left on due to the software upgrade not being completed with the engine running then draining your battery.

This is the main reason they ask for you to remain in the vehicle with the engine running to prevent the radio shutting off during a download or upgrade.

You will see the same warnings on your television, phone or computer when you are updating.

This is from the Subaru software update PDF

IMPORTANT NOTES:

• Do not leave the vehicle once the update begins as ignoring pop-up requests may lead to
battery discharge.

• Do not touch any of the buttons on the head unit while the updating process is taking place.

• If during the updating an error screen is displayed asking “Do you want to Retry”, press
“Retry” to restart the update.
• Once the updating process is complete, the head unit will perform a “soft” reboot.
(NOTE: several “hard” reboots are required to fully install the update. This procedure is
covered in Step 6 below.)
• CRITICAL STEP: After the reboot process completes, press the HOME button to
return to the HOME screen. (NOTE: If the “install message” is displayed asking if you
want to start the update process again, press “Cancel”, press the HOME button again and
return to the HOME screen.)
STEP 6 - Turn the ignition OFF, open and close the driver’s door then remove the flash drive from
the USB port. If an error screen is displayed asking “Do you want to Retry”, press “Cancel”.
IMPORTANT: Wait AT LEAST 3 MINUTES before proceeding to Step 7.
STEP 7- Verify the newly-installed Software Version ID using the following steps:
• Turn the ignition back ON. Confirm the “SUBARU STARLINK” screen is displayed. If
“SUBARU STARLINK” screen is NOT displayed on the first screen, system did not fully
enter “sleep mode” and reboot properly. Perform Step 6 again and wait AT LEAST 3
MINUTES before proceeding.

 

The dealership service advisor did not advise intelligibly with that.

I have not done any of the updates since I bought mine in July of 2021.

I also have not had any issues.

No problems with Bluetooth, Android Auto or any other connectivity problem.

I have gotten an email or two including the most recent one today, but I doubt I will even bother. If it isn't broke...

Unless there are issues, I would take what the service advisor said with a grain of salt.

Following the updates benefitted the dealership more than it did you. Even if it was mostly a bit of distraction/forgetfulness on your part.