Matching separate unicode characters as one
Unicode is a complex beast and database engines tend to be at best superficially aware of it. They certainly don't tend to know about sequence equivalences.

I would suggest making sure that you store data in a consistent normalised form, and normalise search parameters in the same way before searching. I'm not really a c# person, but https://msdn.microsoft.com/en-us/library/ebza6ck1(v=vs.110).aspx looks like a decent place to start for how to go about that.

Obviously you will have existing data that is not normalised, so if you go with this route you'll need to write something to scan the data and replace string values with normalised versions as needed.