Meta Tag Description in disappears on Save

So I’m using the Meta Tag Manager. I set up the description tags in the Manager (Resources >> Manage Meta tags and Keywords) and then I go to the Document itself and follow the instructions:

(To link META tags to documents, click on the META Keywords tab when editing the document, and select the desired META tags and keywords.)

So far so good. Now later if I go back to edit that particular document and save the document, the Meta Description tag disappears on the web page. I’m playing around with it and I’m finding that you have to manually select the Meta Description tag in the Meta Keywords tab each time you save the document. Am I missing something here? This can be a bit confusing for a client to maintain as they’ll have to manually select each tag all over again each time they save the document.

It’s better to use TVs instead, among other reasons for the one you’ve mentioned. I suspect the legacy meta tag system will end up being removed altogether eventually rather than having any fixes applied to it, much as happened to the original logging system.