Why does my T3 show capital gains for a Canadian ETF in Box 21? I never sold any shares and only received dividends. I also never got the cash amount it says per box 21.

As per the CRA - Box 21 – Capital gains
Subtract any amount in Box 30 from the amount in box 21. Include the difference on line 17600 of Schedule 3. All or part of the amount in box 21 may be foreign non-business income, which will be footnoted. Include any footnoted amount for foreign non-business income on line 43300 of Form T2209, Federal Foreign Tax Credits.

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