trasnslation issues with adminAPI

[Peterion]

hey,
I'm trying to translate my shop via using the admin API. 

mostly every thing works fine, but I am struggling with the menu.

as you can see in the Docu TranslatableResources  the ONLINE_STORE_MENU is a resource you can fetch. also the registration via translationsRegister mutation works on paper.  I got no errors back, and when checking the Menu item the registration was correct.

but the menu isn't changing when changing the language.  Not sure what I am missng?

btw. I got this on Focal as well as on Dawn theme.

thx for your help!