The transaction export from the Electrum wallet does not contain enough data to accurately generate a ledger. For this reason, you need to include your Master Public Key the first time you upload Electrum transactions. This is a public key and chain code that can be used to create descendent public keys. In other words, the Master Public Key key allows NODE40 Balance do determine which public keys belong to your wallet.
How to export your Master Public Key
Open your Electrum wallet and select the menu item Wallet => Information.
Copy the Master Public key and paste it into the upload dialogue at NODE40 Balance.