Query -Mixed- in Graph panel - sorting of the results of more than one datasource

Graph panel with query - Mixed - shows the resulting values in the legend in a random order.
It depends on which datasource answers first.

The incoming results of all data source queries should first be collected, then
sorted and then be output. The sorting result should always be the same, even
with multiple data sources in one panel.

My datasoures are: NetXMS server1 and NetXMS server2

My queries are:

A NetXMS server1
Target server 11
DCI: CPU:usage
Legend: server11

B NetXMS server2
Target server 12
DCI: CPU:usage
Legend: server12

C NetXMS server1
Target server 13
DCI: CPU:usage
Legend: server13

D NetXMS server2
Target server 14
DCI: CPU:usage
Legend: server14

My legends are:

First page load
server 12 server 14 server 11 server 13

page reload
server 11 server 13 server 12 server 14

page reload
server 12 server 14 server 11 server 13