It seems like you do not have assign any tag into the existing blog post, but it might related this bug in 5.0.44 version when you trying to add tag in the blog post, it actually didn't add it.

Try download my attached file and replace into this following file JoomlaFolder/administrator/components/com_easyblog/includes/post/post.php

Then try re-add again the tag on the composer, and see how it goes?

Indeed, despite adding tags, they did not save. Unfortunately, even after adding the file you attached to your post, the tags still do not save.

So strange is it can update your Joomla backend and FTP access at ttp://stackideas.com/dashboard/site so we can better have a check?