Steps to reproduce:

1. Open attached project in perforce workspace
2. Connect to perforce and submit project to repository
3. In top menu, click Test > AssetList
4. In project tab notice that Scenes/SampleScene is checked out but doesn't get submitted

Expected behaviour: AssetList used in repro checked scene out so same AssetList should submit scene too

Code which can be used to reproduce the issue:
AssetList list = new AssetList();
list.Add(new Asset("Assets/Scenes"));
Task t = Provider.Checkout(list, CheckoutMode.Asset);
t.Wait();
Provider.Submit(new ChangeSet(), list, "asd", false);

Reproduced with: 2017.4.10f1, 2018.2.0f2, 2018.2.7f1, 2018.3.0a11