Can't update manjaro since days

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# From man pacman-mirrors: Return branch from configuration
pacman-mirrors --get-branch (-G is the short form of the option)

# Print config file to console
cat /etc/pacman-mirrors.conf

This thread might have be helpful: Manjaro 20.2 update?

In this forum, watch the Announcements Category. Pay particular attention to the subcategories of Releases and Stable Updates.