I wanted to use my BCH after the hard fork so I was going to import my wallet on Trezor or Blockchain.info since they support BCH (Electrum doesn't support BCH AFAIK) but it seems both Trezor and Blockchain.info can't recover seed generated from Electrum. Am I missing something ?
Electrum uses a custom mnemonic format so yes Electrum wallets cannot be restored in any other wallet using the seed mnemonic. Instead I suggest installing and running electron cash to get access to your BCH straight away. It's a fork of electrum for bitcoin cash and by default it imports all your electrum wallets automatically. The official site is https://electroncash.org/