I called Turbo Tax customer service in regard to this issue. This is the workaround they provided.
1). On your T3 slips add box 52 & Box 53. (Example: Box 52 = $200 + Box 53 = $500 = Total $700).
2). On your Turbo tax. Go to your T3. Click "Other Boxes".
3). Leave both Box 52 blank (Foreign Capital Gains & Total Capital Gains)
4). Type the total of box 52 & 53 of your T3 slips which is $700 on both Box 53 (Foreign Capital Gains & Total Capital Gains). Click "Done with other boxes". This will automatically update both box 21 amount from box 53($700) (Foreign Capital Gains & Capital Gains).
