Okay, you could use this script instead. It's actually the same script, just working in missionchief and leitstellenspiel.
If this won't work, you could try reinstall tampermonkey and / or delete cache.
Code
const uninvolved = 0; //1 = unbeteiligt Einsätze nicht ausblenden 0 = unbeteiligt Einsätze ausblenden
const patients = 1; //1 Einsätze solange einblenden wie Patienten vorhanden sind 0 = Einsätze mit Patienten ausblenden
var circle = 'width: 20px; height: 20px; border: 1px solid black; text-align: center; border-radius: 20px;';
$(".navbar-right").append('<li><a id="green"><div id="green_circle" style="background-color: #32cd32;' + circle + '"></div></a></li>');
$(".navbar-right").append('<li><a id="yellow"><div id="yellow_circle" style="background-color: #fedc32;' + circle + '"></div></a></li>');
$(".navbar-right").append('<li><a id="red"><div id="red_circle" style="background-color: #c9302c;' + circle + '"></div></a></li>');
if (patients === 1 && $('#mission_patients_'+mission_id+'').html()) {$("#mission_panel_" + mission_id + ".mission_panel_red").show();}
if (recruitment === 1 && $('#mission_missing_'+mission_id+'').html()) {$("#mission_panel_" + mission_id + ".mission_panel_red").show();}
if($( uninvolved === 1 && "#mission_participant_" + mission_id + "" ).hasClass( "glyphicon-user hidden" )){