Node fields and node tokens not showing up in a mini-panel

Hi everyone ! Here's the issue I'm facing :

I made a mini-panel with "Node" as required context. In the mini-panel (composed of three rows) I inserted a view (author infos) and several node "components" :
- the date of creation (%node:created)
- the last date of modification (%node:changed)
- and custom fiedls I've created for the content types the mini-panel is displayed in as a block.

The problem : the node components are not showing up, even the most basic ones (like creation date) !
I've tried to insert it into the mini-panel by "Node", "Node (tokens)", I even created a custom content containing the substitions %node:created, etc. ALL FAILED!

So, do you have any idea why this is not working ?
(I bet it's linked to context as it's the thing I don't really get in Panels...).

Feel free to ask any extra infos you might need... :)