Webassembly cannot input Chinese

I had asked the below question in forum few months ago, about cannot input Chinese in webassembly.

[Two major problem that prevent QT webassembly used in real project. | Qt Forum|https://forum.qt.io/topic/137581/two-major-problem-that-prevent-qt-webassembly-used-in-real-project/2]

and was told such issue may be solved in 6.4.  and then I continue finish other part of my project.

But when 6.4 released and I try it again, I found that issue still exists, and even worse.  In 6.3 I cannot input Chinese words into QLineEdit component, but I can paste the Chinese words into it.  In 6.4, paste doesn't work.

My test project is simple, just drag a line edit into main window. and build and run.  Windows simplified Chinese environment.  Input English in line edit is ok, but no effect when input Chinese with Microsoft input method.

I try paste with two results.  In original wasm_32, It can paste into line edit, but display wrong (two block).  In my build with asyncify support, the paste action doesn't work totally.

This issue is fatal to a real project.