Invalid prop: type check failed for prop "modelValue". Expected String with value "null", got Null

[new-user-name]

Hi,
console says
Invalid prop: type check failed for prop "modelValue". Expected String with value "null", got Null
at <VueDadata modelValue=null onUpdate:modelValue=fn suggestion=null ... >
I added
modelValue = "something"
to suppress warning, but nothing happened. It works fine, but I think something is not idiomatic in my code.

I found that

modelValue: {
      type: String,
      required: true
    },

where String is not just String, but "Allows manipulation and formatting of text strings and determination and location of substrings within strings."