No sim cards detected after OOS 3.2.0

Hi,

I was on OOS 3.1.3 (rooted).

I installed the latest 3.2.0 by:

wiping cache/dalvik
installing full .zip 3.20 via TWRP (downloaded via the amazon aws link)
wiping cache/dalvik
Flashing SuperSU
wiping cache/dalvik
Reboot

Everything seems fine but my phone says no sim card installed. The baseband in About is unknown. And I can't open the screen which shows the IMEI etc on my phone.

Is my EFS wiped out? I made a backup so should be ok. But I am confused as to how to proceed on this?

I have tried to fix this by:

1. Trying to restore the EFS backup using the "fastboot flash modemst1 modemst1.bin" commands (same for modemst2.bin) - I had made a backup of EFS earlier. It doesn't seem to do anything and when I reboot, there is still no baseband.
2. Trying to flash the full ROM zip again - without success

Before I proceed to do anything further, I am hoping someone more intelligent than me can shed some light as to what may have gone wrong and what I can do about it, instead of me managing to make things worse.

Any help would be much appreciated!