Service Layer Credits do not appear for Light and Dark Gray Canvas basemaps when not signed in to an active portal in ArcGIS Pro.

Workaround

Workaround 1

1. Sign-in to an active portal.
2. Create new map.
3. Change basemap to Light Grey Canvas or Dark Gray Canvas.
4. Create a new layout and populate with the map frame.

Workaround 2

1. Manually enter Service Layer Credits by creating a text box.

Steps to Reproduce