The Flexi Zone AF (documented on page 82 of the User Manual) table of contents item is under the "P (Program) Mode" section. Thus, if you're in Auto mode, it wouldn't be available.
My guess that it would only be available in P (Program) or M (Manual) modes. Not sure about Av (Aperture Priority), Tv (Shutter Priority) if they would support Flexi Zone AF or not.
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Ricky
EOS 5D IV, EF 50mm f/1.2L, EF 135mm f/2L, 600EX-RT (x6), ST-E3-RT
EOS C70, RF 24-70 f/2.8L IS, EF-EOS R 0.71x
