I've created a new Support Group for Default Settings i.e. available for all sites.

I then edit the support group and can add a number of techs. Occasionally there will be one tech that will not be listed in available techs.

I check the tech, and they will be associated to all sites.

On the Support Group for Default Settings, tech still not listed.

I edit the tech and remove all associated sites, still not listed in Support Group for Default Settings.

Edit the tech again, and associate them to all sites, still not listed in Support Group for Default Settings.

Eventually I manually edit the tech and add them to the support group manually per site, when there are 30 sites, this can take a while.

How can I fix this?