If I open the instance list in Horizon and have set the default value of 20 entries per page in my settings, the 73 instances in deployment-prep are broken in multiple pages. If I now click any of the table headers (e.g 'instance name') to sort by that column, it will be sorted only for items in that page. Example:

• deployment-aqs01 and deployment-aqs02 are on the second page
• deployment-aqs03 and and deployment-conf03 are on the first page
• Clicking 'instance name', it'll sort alphabetically: deployment-aqs03 in the first row, deployment-conf03 in the second. aqs02 and aqs03 don't show up at all.
• When I open the second page, everything is unsorted again
• Clicking 'instance name' on the second page again, it'll sort deployment-aqs01 in the first and deployment-aqs02 in the second row. aqs03 and conf03 don't show up at all.

The workaround is to go to the user settings and increase the items shown per page, so that everything is shown on a single page.