Hi, we have tried on the front end and it is the same problem. This problem with the index happens on our staging site with no caching tools or plugins, and on our live site when we turn the cache off. I have just tested to index titles and content as well, and that doesn’t work with the index either. When we generate the index, it says it is generating keywords, but it doesn’t work. If i roll back the staging site to 4.23, it works, but when I update to 4.24.1 t doesn’t.
I just tried installing this on a local install with MAMP and blank wordpress and it appears the issue is there as well. I can give you access to our staging site to test?