No "+" - button in specific teams channel available

Hey there,

we got one specific teams channel with no "+" option for new tabs / notebooks etc. as in other channels. I got full permission to this channel.

A long time ago, when MS announced that the wiki-tab will be gone, i exported all other wikis from other channels with no problems, but also in this specific channel where the "+" button is missing, i was not able to export our wiki (the export option was not showing up since then).