Term description and custom fields are suppressed

Yes primarily the function of TVI was to make it easy to swap the default term view out for another display, it does not account for peripheral components in the Content area (other than other Blocks). Does it not render in the Header or Footer area of the configured View?

It does render the Header or Footer area of the configured View but I had wanted to show the term description and an image field I added to the terms on the term pages.

I guess there are various ways of solving that, one could be creating a View block for the header area with the title, description and image.

Okay. I will try it out. Thanks.

The module shouldn't be suppressing any of the entity fields. The view you select should render underneath the rendered field entity, which means you should be able to use the entity display configuration to setup the display of the header to include any fields, such as the description.