n910f baseband unknown after downgrade to KitKat

I have a note 4 (n910F) whose baseband turned unknown and IMEI is gone after downgrading from lollipop to Kitkat. Also the front camera crashes and the fingerprint doesn’t work. Is there any way to repair it? (I have the IMEI written on the sticker under the battery). I downloaded a stock official rom and flashed it using ODIN, but still baseband and IMEI are unknown. Sorry if the post is in the wrong section.