Have electrum connected to my full node and everything looks fine.
Electrum can not connect to full node, electrum is a SPV wallet. But I guess you meant electrum has fully sychronized with the blockchain.
Issue is.. Electrum is showing a balance of zero, when this Trezor has UTXOs.
Still make sure your wallet is fully sychronized with the blockchain
Check your transaction history to check if there is any unauthorized sent transaction(s)
Maybe you are using a very old version of eoectrum, try to update your electrum from eoectrum.org and verify its signature
I believe trying these will be helpful.