Translation of Container from other than default language throws error "Localization failed: container is in free mode or not translated"

[bh-teufels]

Situation:
I have default language DE
2. language EN
and 3. language RU

Language Mode: Connected (Fallback)

now i want to make the translation for RU from Language EN not DE if i did so i get the Error
"Localization failed: container is in free mode or not translated"
(CE's not in Container working, CE's inside Container missing in Translation)
if i make the Translation from language DE (default) it works.

Typo3 10.4.23
b13/container: 1.4.2