Resetting extra_plugins doesn't remove them

Using charm telegraf I configured some manual plugins with:

juju config telegraf extra_plugins="$(cat myplugins.conf)"

those are rendered in /etc/telegraf/telegraf.d/extra_plugins.conf

Then I wanted to remove them and I run:

juju config telegraf --reset extra_plugins

but the content of /etc/telegraf/telegraf.d/extra_plugins.conf was not updated.

As a workaround I had to remove it manually and restart telegraf with:

juju status | grep telegraf/ | awk '{print $1}' | tr -d "*" | xargs -I{} juju ssh {} "sudo rm /etc/telegraf/telegraf.d/extra_plugins.conf ; sudo systemctl restart telegraf"