Hello! It's great to hear from you. If you're looking for the Stock Firmware for the O+ Duo, you might want to try searching for it on the official O+ website or contacting their customer support for assistance. They should be able to provide you with the correct firmware version for your device.
If you've already tried formatting your device through recovery mode and are still experiencing issues, it might be a good idea to consider flashing the Stock Firmware to reset your device to its original state. Just make sure to follow the instructions carefully to avoid any potential issues during the process.
If you need further assistance or have any more questions, feel free to ask. Good luck with resolving your device issue, and I hope you find the help you need soon.
PH