I've recently noticed that there is an error when syncing Polkadot API. Koinly is recording the "Estimated Fee" as the actual cost of the transaction instead of the "Used Fee". The "Used Fee" should be the actual cost. I keep getting "Some of your calculated balances do not match the balances reported by the API." error in my Polkadot wallet and, thus, have to keep editing the synced transaction to input the "Used Fee".

Another recent issue is, when unbonding a amount from staking, which also claims any rewards accumulated, a duplicate transaction is created for those claimed rewards. A Deposit transaction and a Reward transaction for the same amount.