If there were changes made to a token but some transactions are already imported in your Koinly account, these changes will not be automatically applied to the existing transactions.
This article explains how to refresh the token data, depending on what the change was.
1: If token is now tracked
When you imported the token, it was imported with a "grey" (unknown) icon and was missing a market price, but since then Koinly has started tracking this token's price, and it's listed on Koinly's Markets page with a price and logo.
Solution: Use "Change Currency":
☝️ Already merged transfers/trades
If the token change affects the nature of a merged transaction (e.g. it was merged as an Exchange, but now it should be a Transfer because both tokens are the same token) then, after the token change, split such trades and merge them back.
2: If market rates changed
There was an issue with the market rates Koinly had (happens mostly to small-cap, highly volatile tokens) and the database has been updated with new rates, but the transactions in your account still show the old ones.
Solution: Refresh token prices from Settings > Custom prices:
Any other scenario
If the scenarios above don't match your case or you tried both and neither worked, you can always just delete the wallet from Koinly and add it again. Newly imported data will only use the current available rates and up-to-date token mapping.