Issue #3466510: fix #states selector for custom date format.

src/Plugin/CustomElementsFieldFormatter/TimestampCeFieldFormatter.php

@@ -168,7 +168,7 @@ class TimestampCeFieldFormatter extends RawCeFieldFormatter {
     return [
       'visible' => [
         [
-          ":input[name='fields[{$this->getFieldDefinition()->getName()}][settings_edit_form][settings]$path']" => $conditions,
+          ":input[name='fields[{$this->getFieldDefinition()->getName()}][settings_edit_form][form]$path']" => $conditions,
         ],
       ],
     ];