Maximum artifacts size is automatically resetting

Hi All,

As you know if we need to increase file size or set maximum file size of artifact of each job’s then we need to make changes at below url
I have changed Maximum artifacts size from 100 MB to 400 MB but problem is this its getting automatically reset to 100 MB.I could not find out reason of resetting.
I am using on premise GitLab Community Edition (CE) 10.6.3.

Looking for prompt reply.