Advance Search Glitch DT Responsive

There seems to be a glitch in my Advanced Search. I have tried everything.
First it seems to be hit and miss about retrieving listings using keyword only — even through i know it is a valid keyword.
Second and seems to be a bigger problem is the Category box seems to disappear…and the only way you can get it back is to refresh the page. Say for example you search for a category that presently has no listings, and then you decide to look for something in a different category…the word category is there, but there is no box or ability to choose another category.
see wellnessconnection.ca