I presume by this that you mean that
A) Determined that URL is incorrectly Categorised
B) Raised a Case with Check Point to recategorise
C) Whilst waiting then you have placed a Manual Override for the Category in your Management Server
R80.x - New / Custom Application/Site / Override Categorization
https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solut...
Has the peice for R77.x along with fill details of overall process
D) Check Point complete Recategorisation and inform you
At that point you go and remove the manual override created at Step C. It won't remove itself as is purely manual, it isn't looking at the Check Point categorization process to see if matches.