I’ve check your Tumblr.
1. To make sure the filter function work, please use the same filter text with your tag. In this case, you’re using ‘Writing’ for your ‘writing’ tag. It should be ‘writing’.
2. By default, Makna wrap the tumblr post content with link “…“, the hover using that link to show the title. If your content contain link, the title & hover wouldn’t show. So if you want keep the hover style, make sure the post content doesn’t contain link.