Auto Switch Input Method doesn't work very well

Describe the bug
I got some issues while using auto switch input method extension.
I use Chinese input method(Sogou pinyin) in insert mode to type Chinese. Then press ESC, autoSwitch to US to navigate with hjkl. It works very well most of time, but sometimes, when I enter the insert mode, even though I am using the Chinese input method(im-select returns com.sogou.inputmethod.sogou.pinyin), it still types abc, not Chinese expected.

Also, I tried to replace the Sogou input method to Apple Pinyin input method(com.apple.inputmethod.SCIM.Shuangpin), the bug still happened.

Expected behavior
Auto switch to Chinese input method and type Chinese always.

Screenshots

Environment (please complete the following information):

• Extension (VsCodeVim) version: 1.14.5
• VSCode version:1.46.1
  Commit: cd9ea6488829f560dc949a8b2fb789f3cdc05f5d
  Datetime: 2020-06-17T21:17:14.222Z (a week ago)
  Electron: 7.3.1
  Chrome: 78.0.3904.130
  Node.js: 12.8.1
  V8: 7.8.279.23-electron.0
  OS: Darwin x64 19.5.0
• OS: macOS Catalina 10.15.5

Start by reproducing the intermittent behavior in the auto switch input method extension on macOS, using im-select's reported Chinese input method as the observable state. Trace the switching behavior when leaving and re-entering insert mode; done means Chinese input is restored reliably rather than producing ABC text.