se61 zlogin_screen_info empty / changes lost

System language is English, I log in with English, too.

Went to se61, general text, changed zlogin_screen_info, saved, activated.

No change visible on login screen.

Reentered se61 - text looks unchanged.

Searched the forum, the suggestion is to delete the text and recreate it. I did this.

The deletion part worked - the logon screen is now empty.

Creating a new text does not work. zlogin_screen_info exists, but is empty. The logon screen is empty. Changing, saving, activating looks successful until reentering, then it is empty.

Any ideas?