If you entered the foreign income on a W-2 you should not enter it anywhere else. This is just a guess, because I can't see your screen or your tax return. If the amount appears on Form 2555 line 20a you may have entered it as business or self-employment income. In the interview for foreign income there is a screen that asks what form the foreign income was reported on. If you check the box for "A Form 1099-MISC or other self-employment income," then after that you get a screen that says "Enter Your Gross Profit From Foreign Self-Employment." On that screen there is a box for "Foreign Gross Profit." If you enter an amount in that box it goes to Form 2555 line 20a. That might be where you entered the income again. If you entered it on a W-2 you should not enter it again as foreign gross profit. It cannot be both wages and business income.
