While Editing a Task assigned to multiple users, under the Basic Info, there is a drop down called Select. This should allow the user to make changes to the Est hours and cost for each user. However, after making changes and hitting save, if the user re-edits the task and goes back to select no changes are saved. The changes also do not reflect on Est hours under Effort on the same screen. 

Page: Project>Edit 

Reproduction: Select the 'Select' drop-down under Basic Info on the right side. Make changes to cost and hours. Select confirm and then save the task. Edit the task again, go to 'Select', no changes are seen. Scroll down to Effort, no changes are seen in the Est hours under Effort. 

Recommendation: I recommend changing the name of the drop-down from Select to something else. This does not signify the purpose of the drop-down.