EF Core 5 – How can I use EF.Functions.Like with a custom property that maps to a JSON string?

In one of my DB models I have a property with a custom type (Dictionary<string, string>), which is automatically converted to/from JSON with a custom converter, and is stored as a text field in the database. I would like to be able to use MySQL’s LIKE comparer to search for a string within this JSON field, but I am getting an exception. I don’t care about the JSON’s structure, I’m fine with treating it as a simple text field and searching in it that way.