I did as you said, checked all of the individual "Used" addresses from the Electrum wallet, including the Change used ones, in the block explorer, and voila ! Yes, I do have exactly the amount of BCHs that I was expecting.
This would indicate that your sweep into Coinomi failed... if the BCH is still sitting in the Electrum addresses, then they have not moved, so the sweeping transaction has not worked.
I also have Electron Cash desktop wallet installed in a virtual machine. Yesterday I created a wallet there using the Electron wallet's seed. No BCHs there... Strangely the addreses that show in Electron Cash don't coincide with the unused addresses in Electrum (there is no option to see "used addresses in Electron Cash"....this is mind boggling....
If you imported your Electrum seed mnemonic into ElectronCash and got different addresses and no BCH balance... then the seed mnemonic you imported is NOT for that Electrum wallet. The two apps are pretty much identical (except for the BCH mods to ElectronCash), so any given mnemonic seed should generate the same addresses in Electrum or ElectronCash.
I'd suggest you double check in Electrum what your seed mnemonic is... also, try and import that seed mnemonic into a new Electrum wallet and see what addresses it generates.