Did you ever install a custom recovery? If so reinstall MDL modem. But I really doubt you do, since you didnt mention it, so you will probably need to odin back to stock.
Here is the xda thread on it, be sure to read it and do exactly what it says
after looking at it again, having unknown on IMEI is usually bad and unless you backed up your EFS, you may not be able to restore it. Samsung can fix it, but since you rooted you technically voided the warranty, but they dont always check. but the thing i cannot figure out is how you lost root after a factory reset. this does not remove root, so im not really sure but something doesnt add up