Once you submit an experience for Rockstar verification, like a job, tour, or gig, it is locked so that you can not edit it any more. That's so someone can't get verified for one job and then go back and change the description into something different.
It is possible to edit a verified experience, but it will lose its Rockstar verification, and you will have to use one of your verifications to get it re-verified. Before you make a change, there is a warning message that explains this.
If you need to make a minor change to an existing Rockstar-verified experience, such as correcting a typo, please open a help ticket or email firstname.lastname@example.org with the information we'll need to make the change.