Heres an easy fix that you might do without the need to call up a professional.
Simply watch this video tutorial byAndrea Jean Cleaningon YouTube and learn it step by step.
Pull up the drain stopper and twist until the gasket completely releases from the sink.

Image Credit: Andrea Jean Cleaning via YouTube
Insert the drain stopper back into the sink making sure to stick it in as straight as possible.
Then, reassemble the pivot rod underneath the sink.
*Thanks toAndrea Jean Cleaningvia YouTube for all images used here.

How To Remove & Unclog A Drain Stopper
