I'm gonna reply to my own post in case someone else face the roblem above.

Uou can't use your private key in case your wallet had a 2fa on any electron version above 2.9.3

here some post of people facing the same issue:

https://www.reddit.com/r/Bitcoincash/comments/7ee74h/claiming_bcc_from_electrum_2fa_wallet/

https://www.reddit.com/r/Bitcoincash/comments/7fhj61/should_have_almost_8k_of_btc_cash_but_electro/


here's the link to electron cash 2.9.2 (linux or window)

https://electroncash.org/downloads/2.9.2/win-linux/

Hi guys!
Today I decided to move all my funds on a KeepKey.
I succesfully moved all my bitcoins to it, and then I started googling how to get my Bitcoin Cash.

First of all, I can confirm that some of my BTC were stored before the fork:
https://www.blocktrail.com/BTC/tx/6d0192054857cabe8f434438addd0870d056f28b9dfeb1ac52fe44183cdabaf1

Now, I Downloaded the Electron Cash Portable 3.2, and tried all following:

1) 
     - went to File and selected  New/Restore
     - selected standard Wallet
     - selected I already have a seed
     - pasted my seed, but the "next" button remains gray
I could check the BIP 39 SEED into the option modal, but it was a 2fa wallet so the checksum wouldn't  be correct

2)
     - went to File and selected  New/Restore
     - selected Import Bitcoin Cash Addressses or private keys
     - pasted all the addresses exported from the electrum 3.13 wallet
     - GREAT, my balance shows up, but i cannot spend it

3)
     - went to File and selected  New/Restore
     - selected Import Bitcoin Cash Addressses or private keys
     - pasted all the private keys exported from the electrum 3.13 wallet (same file above)
     - typed my password (twice obviously)
     - Balance 0. BCH


So, I need either a solution to verify the wallet obtained on the 2nd try, or figure out why there's 0 balance on 3rd try


Any suggestion, or workaround, or another solution? :|