It sounds like what is happening to you is the same thing I described that happened to me. Use bitaddress.org and ensure you're not importing the wrong key. The public address you're looking at may correspond to the uncompressed private key but you might be importing a compressed private key. That's what happened to me. If you load up your private key on bitaddress, you'll be able to see both the compressed and uncompressed private keys. Did you notice the public address in Electron Cash? Is it different than what you see on blockchair? If so, that's what happened to me. Just make sure you have the right private key for the right public address using bitaddress.