Disabling auto-translation from English to another language?
You can configure the administration language seperate to the content language by setting:

/admin/config/regional/language/detection:
Account administration pages: enabled


If you want to force this, set this setting at the top of the list.

Then there is in the user configuration of admin's the option to set a different language for the site and the administration pages language.

For other roles, just set the permission "Use the administration pages and help" to allow this setting to appear on the user page.