not honoring value mappings

The Matrix does not appear to be honoring the value-mappings

Here is an example

Note the hostnames are just the hostname prefix but when I apply this with the matrix

It does not honor the value mapping

Start by reproducing the Matrix panel example with the shown value mapping and compare the displayed hostname prefixes with the mapped values. Trace how the panel receives and renders value mappings; done means the Matrix display uses the configured mapping consistently.

Written by the indexing model from the issue text.