Steps to reproduce:
1. Create an empty project
2. Create two prefab objects
3. Enable Collaborate in the project
4. Right click on the first prefab object -> Collaborate -> Publish

Expected: Collab pane opens with a selection
Actual: Collab pane opens with a selection for only a brief moment, and comes back to the usual collab pane (which offers to publish all changes)

Reproduced on: 5.6.3f1, 2017.1.1f1, 2017.2.0f3, 2017.3.0b1

Notes:
* around 1 in 10 times it is possible to get the collab pane to stick with selection
* 5.6.3 opens a different kind of pane, as such, it is not affected by this issue, but after clicking "Publish" nothing happens