The balance you see on the Top Panel on your login displays your in-app wallet balance on Zenland. This is the balance from where the service fee is deducted when the contract is being deployed to the network. Learn more about the Zenland fee and how it is paid.
This balance is different from your Metamask wallet balance which is used to transfer the agreed amount (escrow funds) into the contract and pay for other network transactions.
If the service fee (Zenland fee) displayed in the escrow contract form exceeds your in-app balance, the contract cannot be deployed until enough funds are added to pay the fee. Read this explanation on how to add funds to your internal wallet.