invalidateSize, hidden div map

Hi, i hope you’re still around, thanks for your plugin, it’s working well for me.
I only have an issue to call invalidateSize() on the map when it’s in a hidden div.
I managed to use it successfully in a front end form using window.maps[uid].invalidateSize(), however i can’t seem to find the right variable that is applied to the map to do it in a normal post.

Can you maybe help me with this?

Thank you very much!
Michael