Error comparing two strings in an if in twig

I have an error comparing two strings in twig .

Here is an example of my code:

{% set var1 = "" %}
{% set var2 = "" %}
{% for unidad in array %}
    {% if unidad.var1 == var1 %}
        {% if unidad.var2 == var2 %}
            <tr>
                <td>{{ habitacion.var1 }}</td>
                <td>{{ habitacion.var2 }}</td>
            </tr>
        {% else %}
            <tr><td>---</td><td>---</td></tr>
        {% endif %}
    {% else %}
        <tr>
            <td>|{{ unidad.var1 }}| |{{ var1 }}|</td>
            <td>|{{ unidad.var2 }}| |{{ var2 }}|</td>
        </tr>
    {% endif %}
    {% set var1 = unidad.var1 %}
    {% set var2 = unidad.var2 %}
{% endfor %}

The problem is that the loop does not enter the if , with the two variables being the same in some cases. I show you the output screen in a loop loop that does not enter the if :

<td>|NORMAL| |NORMAL|</td>
<td>|311| |311|</td>

I have also tried to put the if in this way:

{% if unidad.var1 is same as(var1) %}

But it does not work either.