Hi. I visited your link and this CSS can help:
body.post-type-archive-tribe_events #tribe-events-pg-template .tribe-events-title-bar {
height: 150px;
}
However, this doesn’t take into account responsive design or address “why” this is happening.
You might try playing with this setting: wp-admin > Events > Settings > Display tab > “Events template” option — to see if changing it makes things work better for you.
If that doesn’t work, I’d suggest asking your theme author how-to for the tribe_events custom post type archive view.
Please let me know how this goes for you.