How to define straight and curly apostrophes which are treated the same

I built the events listing website using Events Management plugin. In WordPress, ‘straight’ and ‘curly’ apostrophe are treated as separate entities. I would like to know how to define straight and curly apostrophes which are treated the same in WordPress frontend/backend.

My site is here – http://ottawatourism3.ca/events/

Currently my site uses the ‘curly’ apostrophe. If I search “Father’s day” – using the curly apostrophe at the Events Manager’s event search, a subset of extant instances show up. If I search “Father’s day” – using the straight apostrophe, nothing shows up. I did same thing at the event search in the admin and the result is same.

I really want all events with straight and curly apostrophe to show up when I search events with straight or curly apostrophe on both backend and frontend searches.

I would really appreciate it if I could get assistance with this issue.

http://wp-events-plugin.com/