I posted earlier that after using Evernote for years I was suddenly unable to add a new tag. But after posting that, I noticed the tag had been attached to the note. What I didn't realize was that I was looking on my iPad, whereas earlier I had been looking on my desktop. So, the new tag is there on both my Android phone and my iPad and it attaches to the note in question. However, on my desktop version, even though the tag shows in the list of tags I can use, it will not attach to the note.
In fact, the particular note I am referring to shows four tags on both the phone and iPad, and none at all on the desktop.(even long established tags that I have used a lot)
I normally prefer to use Evernote on my desktop, and only use my phone or my iPad when I need to attach a screenshot or photo from one or the other.
Evernote 10.98.3 on a Mac desktop running Sonoma 14.5