I've noticed in more than one account (I have multiple Koinly accounts) that something seems to be wrong with the USDC transaction fees calculation in the Coinbase integration. All cases I noticed were related to recently added transactions that were added using the Coinbase API (maybe they changed the data structure that comes through their API?).

The calculation seems to be wrong and "Missing purchase history" errors of small USDC values start to pop up. So far, I've only experienced this issue on transactions involving USDC.