MQTT tag for powerChart

Beginner on Ignition, I am trying to use data from a MQTT tag who has history enabled (SQlite DB) to feed a powerChart. For some reason, when I open the power Chart's the tag browser to select this same tag, I can't find it.
My tag is visible in the main tags browser window under the "MQTT engine" menu and the values are updating. Is there something to do to make it available for select in powerChart?