SVG Image bundle label not presenting correctly

Problem/Motivation

I am using the SVG Image Field and SVG Image Field - Media Bundlemodules very successfully to build a media library which comprises two Media types:

1) 'Raster (bitmap)', machine name: image - The CORE Media module default...

2) 'Scalable (vector)', machine name: vector_image - The SVG IMAGE FIELD - MEDIA BUNDLE Media module default...

I can create and edit both types of media exactly as expected.

When I visit the CORE Media Library page, I can: (1) 'filter by' both types and (2),(3)'view' the Types using their human-friendly names...

The problem

The problem arises when I build an Search API index view of Media and then try to set up a Facet filtering on Media type.

I have added the correct field to the Search API index...

Normally, I routinely choose the 'Transform entity ID to label' option but when I do this on the Media type facets, the new 'Scalable (vector)' label does not show up...

HOWEVER, if I switch OFF the 'Transform entity ID to label' option on the facet it shows up and the facet filters the results exactly as expected proving to me that the index is actually working as I expect...

Might there be something amiss that stops the bundle presenting its label?

Any advice on what to try gratefully received.

Thank you