src/Tools/VSCode/src/vscode_rendering.scala

       val context = language_context(caret_range) getOrElse syntax.language_context
 
       val line = caret_pos.line
       doc.offset(Line.Position(line)) match {
         case Some(line_start) =>
-          syntax.completion.complete(history, false, true,
+          syntax.completion.complete(history, unicode = false, explicit = true,
             line_start, doc.lines(line).text, caret - line_start, context)
         case None => None
       }
     }