Hi, Adam.
It's possible that a user of your GA4 property accidentally unpublished the Acquisition collection.
To re-publish the Acquisition collection,
1. Mouse over the left-hand menu and click Reports.
2. In the bottom-left corner, click Library.
3. Under Collections, in the top-right corner of the Acquisition box, click the three vertical dots.
4. In the pop-up window, click Publish.