Realign assignments to demand issue

I assigned some resource assignments on a demand to match the requested start date and requested by date

Then extended the demand by moving out requested by date. 

Then clicked the UI action link called  "Realign assignments to demand"

I think it is supposed to readjust my reasource assignment and those resource's allocations to match the new dates on demand. But nothing seems to be happening. WHen I click on the UI action, it comes back on the same page but resource assignments are not adjusted for dates. 

 

Am I missing something or is there a bug in the product