This is the final OTA update that Harman produced for the Invoke. It was silently published to the Invoke's product page here as a FAQ question on September 8, 2021. The page is archived here.
It is mirrored here for archival purposes. Instructions for WIndows users are included as a PDF inside the ZIP file.
This is a system image with an adb shell over the network enabled, and updates disabled by blocking the domains through the hosts file. The boot sound has been replaced to indicate that this is a custom, unsafe, image, and should only be used for development/research. And it's loud on the first boot, sorry.
For some reason, the setup/wifi AP creation process will fail to start sometimes, just hold the mic button for five seconds if this happens.
Use the tools released earlier to flash this file.
Do not attempt to flash any other image than the one mentioned in the instructions, they will brick the Invoke even worse, as they are not for the Invoke, and will make it currently unrecoverable, possibly needing hardware mods to recover from this type of brick. I have already bricked a spare Invoke from experimenting.
Initially provided by Reddit user theace69 and later officially posted to Harman's support website, this archive contains the tools and instructions to reflash your Invoke back to a firmware that includes Cortana. I would recommend using Linux if possible to perform the flash, you will need to run the run.sh file as root, as I had issues with Windows detecting the device properly, probably due to the rapid disconnects/reconnects the Invoke does while booting into flashing mode.