Redirection issue with subcategory install

Hello,
I’m running multilingual press with category install (like /uk) on several sites. My problem is that ALL /wp-admin are not working for all languages like /uk/wp-admin for example. I checked htaccess and wp_config and there was no issue. I asked my hoster if it is anything on their end but they say it’s not. Something just triggers a redirect that is lost.

My settings are 100% according to this guide:
http://make.marketpress.com/multilingualpress/tag/htaccess/

And it worked in the beginning but later it is not any more.

I’d appreciate any help.
Thank you

https://ww.wp.xz.cn/plugins/multilingual-press/