Hello,
Thanks for the feedback, and sorry for the late answer.
I just tested the Field Group Taxonomy Location, and it works fine on my end. Here is a video of my test.
Did you manage the fix the issue since then? I would suspect a conflict with some custom code either in your theme or a third party plugin.
In order to isolate the issue, I would recommend clone your website on a development / staging environment using Duplicator, or your hosting’s backup solution. Then try to disable all your plugins one-by-one (at the exception of ACF Pro & ACF Extended) until you find which one cause the issue.
If the problem persists, try switch to the native WP Twenty Twenty Two theme, to make sure you don’t have any custom code in your theme which would break the feature.
In all cases you should be able to confirm it works like I did, by setting up a clean WP install with ACF Pro + ACF Extended only.
You can read more about how to setup a favorable environment for debugging WordPress & ACF in our guide here.
Let me know if you found something!
Regards.