Have you backed up your imei? That is of utmost importance.
The same thing happened to me. Hell, I couldn't even go back to 4.2.2, but I figured out I was doing something wrong. What I did was flash the stock firmware that came with my phone, which bought me back to 4.2.2, with the upgraded bootloader. As my phone turned on I was surprised to see that I didn't see the setup screen, but instead it booted directly to the home screen. The brightness was at full and all the features were on. I saw yellow text with some kind of hardware message. The Imei was 0049, thankfully I had a backup. Afterwards I rooted; subsequently flashed TWRP and restored from a backup. After that everything was back to normal.