pszurgot

Use ACF 5.8.2 or use qTranslate-XT (it works with acf 5.8.3 and this plugin). https://support.advancedcustomfields.com/forums/topic/media-library-broken-after-update-to-acf-5-8-3-with-acf-qtranslate/

Use q-translate-xt rather then this old plugin. The new version of this plugin q-translate-xt includes this plugin "acf-qtranslate". https://github.com/qtranslate/qtranslate-xt.

I have been testing this solution for some time and have also implemented it on production versions of websites. Everything works great. In my opinion, there is no point in...

Custom fields WYSWIG works like a charm on my sites.

Yes, XT. I didn't have to change anything in the ACF fields. Everything worked fine.

Yes, you need only "q-translate-xt". Turn off "q-translate-x" and "acf-qtranslate" plugins.