I have the same problem. I noticed it a week or two ago and hoped that the next update would fix it, but unfortunately it did not. The October cumulative update was installed on my system 10/9/24 and the issue remains.
Windows 11 File Tags Autocomplete Not Working
Usually when I try to add EXIF tags to my files in Windows 11 File Explorer, it will show a list of autocomplete options, making it much easier and faster to add tags. However, the autocomplete has stopped working for me. It was working just a few days ago, but since then I installed the "2024-09 Cumulative Update for Windows 11 Version 23H2 for x64-based Systems (KB5043076)". I suspect something in this update made this feature stop working. I've already used services.msc to make sure Windows Search is running, and checked the Indexing Options to make sure the folders that the files I'm trying to tag are in are under the included locations.