Adding a new link to link controller Active/Pasive cluster

i have added a new Link to Link Controller cluster, i added the link via wui, self ip also and all the basic settings, then i modified the gtm server using "modify gtm server ...." to add the new link ip adresses (for both machines) and "save sys config gtm-only" ....after few seconds de config dissapears. i have tried disabling the gtm config sync and auto save...but the changes are missing after few seconds. is this a known issue?