System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.71

Blender Version
Broken: version: 2.91.0 Alpha, branch: master, commit date: 2020-10-19 22:48, hash: rBea4d28aea034
Worked: (newest version of Blender that worked as expected)

Short description of error
This issuse occurs when tpye in Chinese amost in every namable field:

(naming objects)
In the above images,I'm using default microsoft Chinese input method.When typing "你好“, the keyborad input is "nihao" but the first letter is doubled;when typing "嘿" the input is "hei" but the first letter also doubled.

(changing the content of a text strip in VES)

(in output feild)

(naming modifier)

Exact steps for others to reproduce the error

I'm using Win10 OS and if you are using Win10 too you can intall a new language through settings->time & language->language and add Chinese(for quick search you can copy this key word "中文"(no quotes)).