I arrived in Cebu two weeks ago with my Filipina wife and my son who has dual citizenship.
We will stay for four or five months.
Usually I extend my 21 day visa at Immigration in Mandaue whenever it expires.
However - on entry this year my passport has been stamped with a one-year visa.

Is this a mistake? Or am I now entitled to a 1-year stay because of my son?
And if it is a mistake, should I go to Immigration after 21 days or just take my chances at the airport when we leave in a few months?

thanks in advance for any help!