I cannot add my own tags

I've tried to add my own tags to items and people on here but it will no longer let me add tags to this site.

I don't understand why

Does this happen to all pages? Are you trying to add tags on the item pages direct or though the collections pages?

Yes, it happens with with every page. Like say celebrity pages, it won't let me tag celebrities.

& I don't understand why this is.

You can try to update the browser or go here through another

I doubt it's because of my browser. I use Google Chrome.