Theme conflict?

Hey there!
I’m having a bit of a problem getting the scheduler functional and was hoping you could steer me in the right direction so I have more details when I contact my theme’s developer. The theme I am using is Salient. My dropdowns aren’t functional and there seems to be a wonky scroll issue.
Any tips?
http://www.dangerawesome.co/book-online/

Thanks so much,
Morgan

https://wordpress.org/plugins/birchschedule/