Comments feed for each category

Hi,

I would like to provide an RSS Feed for the comments of each category.

I searched and found these resources:
https://core.trac.www.ads-software.com/ticket/9630
https://www.ads-software.com/support/topic/264654?replies=3

I’ve tried to use the URIs suggested but nothing works. I get a partial RSS Page but with no content.

Here is an example:
https://www.planetphillip.com/posts/category/single-player-mods-and-maps/comments/feed/

I’ve tried category IDs but that doesn’t work.

I am unclear if it’s a bug in 2.8 or I have missed something.

TIA
Phillip