Template.registerHelper - Strage behaviour?

I have two Template.registerHelper's in a template and this template is called on an events event in another template as:

     "click .examine": function(event){
         Meteor.call('getDetailsUser',keyImg,keyUser, function(err,result){

In the template rendered, I have this html:

{{#if liked likes}}
    <button type="button"><i class="fa fa-heart fa-2x"><span class="badge fontScale roboto">{{likes.length}}</span></i></button>
    <i class="fa fa-heart fa-2x"><span class="badge fontScale roboto">{{likes.length}}</span></i>

{{#if wanted user key}}
    <button><i class="fa fa-tag fa-2x"></i></button>
    <span><i class="fa fa-tag fa-2x"></i></span>

The Template.registerHelper - wanted works fine so if a user clicks the button, it reevaluates this condition to return false. However the Template.registerHelper - liked does not reevaluate the condition on button click:

Template.registerHelper ('liked', (a) => {
    var isLiked = true;
        if(Meteor.user()._id == el.userLike) {
            isLiked = false;
    return isLiked;

Template.registerHelper ('wanted', (a,b) => {
    var wanted = Meteor.user().want;
    var isWanted = true;
        if(a == el.usersType && b == el.match) {
            isWanted = false;
    return isWanted;

I know the Template.registerHelper - liked works because I call it in another template and it’s fine.

What would prevent it working in this instance?