When a transaction fee is paid on an L2, the amount is the sum of an L1 fee and an L2 fee. This is accounted for correctly in Koinly for networks like Optimism.

For some unknown reason, Koinly transactions for Blast only include the L2 fee. This causes the ETH balance to be incorrect, since it is missing any amounts paid for the L1 fee.

Currently having to manually update any Blast transaction fees to include the missing L1 fee, otherwise the wallet is never in balance.