When my page is displayed, I push some data to Google Tag Manager (GTM) dataLayer: 

```
dataLayer.push({
    event: "MY_EXPERIMENT", 
    variant: "A",
    result: "FORM_DISPLAYED"
});

```

When the form is submitted, I push some new data:

```
dataLayer.push({
    event: "MY_EXPERIMENT", 
    variant: "A",
    result: "FORM_SUBMITTED"
});

```

I've created dataLayer variables in GTM, and I've inserted those in the category/action/label fields of my tag in GTM. One of the variables is setup like this:

The tag is triggered by URL path, and in preview mode it works.

However, when I look the event up in the live dashboard of Google Analytics, only "undefined" is displayed in the category/label/event columns. It seems to me the variables are not set up correctly, but I've looked through everything and it seems just fine. 

What am I doing wrong?