Windowless richedit controls cannot enter emoji

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C++

MFC

When I use Windowless RichEdit Controls(ITextHost, ITextServices), I found that if I enter an emoji such as 😄, it will become □.

And if I use CreateWindowEx to create a RICHEDIT50W, all emoji is correct. But if create a RICHEDIT20W, enter emoji will become □.

Is Windowless RichEdit create RICHEDIT20W? How can I use Windowless RichEdit to create RICHEDIT50W?

What I have tried:

I use CreateWindowEx to create a RICHEDIT50W, all emoji is correct. But if create a RICHEDIT20W, enter emoji will become □.