Can't create site term group as site administrator

Question

I'm trying to add a site term group (and terms) using the new term store experience. I'm using a default communication site and also tried a group connected teams site.

I simply don't have the "Add new term group" button and term store says "You have view-only access to the term store properties.".

I have tried adding myself as Site Owner (next to being site admin) - no change.

When I add myself as global term store administrator, I can create a term group within the site. I can then assign myself as contributor and then remove myself as global term store adminstrator and can readily work with the term group within the site collection.

1. Are site collection term groups not something we do anymore? Are they pretty much "Not supported" anymore? (do note that the documentation doesn't talk about them: https://learn.microsoft.com/en-us/sharepoint/set-up-new-group-for-term-sets)
2. Is the process I described the "correct" process, as-in "ask your local term store administrator to add a term group to your site, and add you as the owner of that group"?
3. Am I missing something?

Note: I am not talking about global term groups/sets - site collection level only. It used to be that you are the boss of your site collection as site admin, but either I am doing something wrong or something changed.

Answer 1

Seems like this has indeed changed. I was able to reproduce the behavior you described.

I also managed to find a workaround to create the term group/term set as site collection admin using the following article.

https://learn.microsoft.com/en-us/sharepoint/troubleshoot/administration/create-default-site-term-set

Seems like site collection term stores are now switched off by default on modern sites.