Abstracts which are assigned wont be unassigned from someone automatically even if they have updated their topics/expertise. The reasons include that they may have already submitted reviews on some of those abstracts, they may have wrongly changed the topic among other possible reasons we never made the unassignment automatic.
For unassigning abstracts manually, you can do either of the following:
Method 1:
Go to Manage/Assign abstracts
Select abstracts which you want to unassign (you can select up to 30 abstracts at once)
Click on “Assign Reviewers” button in the top right corner
Select the reviewer/s you want to unassign from the selected abstracts
Click Unassign
Method 2:
Go to Contacts
Search for the reviewer whom you want to unassign abstracts
Click on Reviewer’s name to go to their profile
Click on Reviews tab
Click on Unassign button to unassign abstracts one by one
Method 3:
Go to Manage/Assign abstracts
Search for the abstract from which you wish to unassign reviewer
Click on Reviewers & Reviews tab
Click on Delete icon besides the name of the Reviewer whom you wish to unassign from this abstract