After contacting Turbotax support they instructed me to do as follows:
1. go back to the page in which I filed out the amounts of foreign tax utilized in each year
2. for each year in which the "utilized" value is higher than the "foreign tax" value, I should instead set utilized to be the same as the foreign tax, and the difference should be included in the "utilized" from a previous year (I assume it's better to add to the earliest year, so you get to retain the carryovers for longer).
I hope that helps.
