Problems with slug / unrequested change of languages

Hello,

We encountered an issue with the slug on multiple WordPress instances based on different languages. For example, in case you would like to switch from https://www.domain.com/home to https://www.domain.com/contact the next page will be on the wrong language, e.g. https://www.domain.com/es/contact.

We are using following plugIns:
Visual Composer
qTranslate-X
Visual Composer & qTranslate-X
qTranslate slug

Do you know of any solution to eliminate this unrequested change of languages?

Thank you in advance!
Kind regards