problem with tags after installing Ceceppa Multilingua plugin

Hello there,

I have recently added and adjusted Ceceppa Multilingua plugin to https://thewandernotes.com as my client needed a language switch.

After installing this plugin I have noticed that when I click on a tag at the right of the site it redirects me to a blank page, although the browser bar has https://thewandernotes.com/el/tag/(tagname)

I am sure that the problem is with Ceceppa Multilingua as when I deactivated it, everything worked.

I definitely want that plugin because it has everything my client needs. As new to WordPress, can anyone help me to solve this problem?

thank you very much