Cannot Add Tags in Composer

Hello Support,

For our client: https://www.ctnsolutions.com, we cannot add new tags through the composer, (when adding a new blog post or editing an existing post.) The tag will show up, but when you save the post and then go back into edit it, the tag will not be there anymore. We have determined it is not a disk space issue. We are able to add tags through the tag manager in Easyblog and the database, just not through the actual composer itself.

Their Joomla version is: 2.5.28 and their Easyblog version is: 5.0.44 We are not able to upgrade Easyblog, as my understanding is that the 5.0.44 is the last version that works well with their Joomla version. Can you please look into this for me and see if there's anything we can do besides upgrade their site and Easyblog? (At this point, upgrading is not an option.)

Thanks!