Hi,
I have checked and I see that it is related to your menu system. For example I see the following CSS code which sets minimum width to 200px. It is in /wp-content/themes/classipress/assets/css/A.foundation.min.css file.
.is-dropdown-submenu {
display: none;
position: absolute;
top: 0;
left: 100%;
min-width: 200px;
z-index: 1;
background: #fefefe;
border: 1px solid #cacaca;
}
I would recommend to play with it or consult your theme developer. It is not a trivial task to solve and at the same time not break other menu functionality.
We have multiple options to display the language switcher. For example you can use [gtranslate] shortcode in the menu to display flags side by side instead of having sub-menu items for it, since you have only 2 languages. Please check Positioning tips for more info.
Thanks! ??