Loading firmware into Netgear MR1100ss-2A1NAS router

So, I bought a nighthawk new years ago from ATT, about 6 months into the plan my device went bad. I sent it in and they gave me a replacemnt. Fastward 4 years and they will not unlock it because the EMEI number is assigned to a different account. Most likely the person who sent theirs in for repair and got a exchange like I did.

I download the following:

MR1100-100NAS_23113828_NTG9x50C_12.06.11.00_00_GenericNA_05.03.secc.spk

FDT 4.6.2.0

I put the device into BootHold

telnet 192.168.1.3 5510 then AT!BOOTHOLD (I get a OK back)

Run FDT <firmware name here> and get this:

FDT version: 4.6.2.0

Checking modem mode ...

...

Firmware download failed.
Primary error code: 82 - Failed in checking modem mode.
Secondary error code: 5 - Neither NDIS adapter nor serial port is available.
Total time elapsed: 120422 ms.

I tried two different USB-C cable but no help there....

What am I missing?