keywording issue
I've noticed lately that when I'm exporting photos from my catalogue that the exported images are picking up some metadata from an old image (but not all the time, only now and then!).
I don't have any presets selected and the auto-write to XMP is checked in Metadata field in the Catalog Settings.
But for some reason, it's still exporting keywords that I entered for a particular set of images ages ago, even though they aren't displayed in the Keywords Tag field!
If I change the dropdown arrow here to 'Will Export' it does show these erroneous keywords, but there's no way of removing them that I can find. 
Any help would be appreciated! Thanks.
(First pic shows the keywords I've entered for this particular pic that I want to be saved down. Second pic shows the actual keywords that are being saved. Running up-to-date Lightroom Classic on Windows)
