I was working on the assumption that you are linked to the TurnKey Hub!? Is that the case, or are you running in "solo" mode?

If you're running in "solo" mode, that might explain it. To do that, you either need to generate your own profile, or use an empty one. If you use an empty one, then it will only backup the DB by default, to include other files, you'll need to add them to the overrides file (/etc/tklbam/overrides.conf).

If that's not the case, then I'm not really sure what could be wrong? Perhaps try manually clearing the cache files? I.e.:

rm -rf /var/cache/tklbam/*
rm -rf /var/cache/duplicity/*

Then run it manually again.

If it still doesn't work, please post the full output of TKLBAM, plus the output of these:

turnkey-version
apt policy tklbam
df -h