FX bay: multiple selection bug, deletion doesn't work

In the FX Bay, when you try to remove several effects at once one or two of them are not removed.

Steps to reproduce:
1. Create a project.
2. Add a track, add two or more (different) effects to it.
3. Open Project Media/FX Bay, FX tab.
4. Click the first item on the list, Shift-click the last one to select all effects. Alternatively, Ctrl-click several items. Alternatively, select "Select all items" from the context menu.
5. Press Delete or select Retain/remove -> Remove from project.
6. One or two of the selected items are not removed from project and are still selected in the list. Besides, Undo history doesn't reflect the deletion properly.

Using Reaper 4.611 on Windows x64.