Languages URLs not correct

Hello.
As I already wrote, FC from master branch have big problems with multilingual sites.
This is how looks languages module with latest FC 4.2.1 (it's ok):


Aтв this is how looks the same module with FC from master branch:



All URLs have current language prefix.

hello
this demo site with last master update (today) + joomla 5.3.1 doesn't have your problem
flexidemo.com3elles.com/jobboard/demoj4/...offers/gardener.html you can switch to any language without problem url is good

I have Joomla 5.3.1
Updated to FC from master branch - same problem.
Which FC file is responsible for generating these URLs?
I'll try to fix it.

as i say that works out of box, maybe a plugin problem ? SEF rules ?

This occurs on two different multilingual websites (J4 and J5). It only occurs when FlexiContent item view. There are no issues with menu items.