Smartblog creates a new URL with duplicated content when using the language switch

[DTR]

Hi, I don´t know if anyone else has gone through this problem or can help me

Smartblog doesn´t redirect to the correct URL when I use the language selector widget.

Let´s say I want to translate this page from spanish to german:

https://www.deportrainer.com/es/blog-deportrainer/128_comprar-maquinas-hammer-gimnasio/

I set up the following URL for the german version from Smartblog backoffice: 

https://www.deportrainer.com/de/blog-deportrainer/128_hammer-machines-gym-kaufen

The problem comes when I change to german language with the switch in the front office.

It redirects to a new URL for the german page with the form: 

https://www.deportrainer.com/de/module/smartblog/details?id_post=128

So, now I have two URLs for each language and duplicate content.

Anyone managed to solve It?

I tried 301 redirection but It didn´t work.

Edited June 16, 2022 by DTR (see edit history)