weird windowUnfocused event from window.filter

[wd]

with this code

watcher = function(win, name, event)
  logger:i("event: " .. event)
  logger:i(win:id())
end

obj.start = function(apps)
  for _, v in ipairs(apps) do
    app = wf.new{v}
    app:subscribe(
      {
        wf.windowFocused,
        wf.windowUnfocused,
      }, watcher)
  end
end
obj.start({Logseq})

I will get a weird windowUnfocused event. this is the log. After reloading the config, I focused on the application Logseq and will get the windowFocused, but just after some seconds, I'll get the windowUnfocused event. Why does the windowUnfocused event happen?

2022-04-03 16:04:16: -- Loading ~/.hammerspoon/init.lua
2022-04-03 16:04:16: -- Loading Spoon: RecursiveBinder
2022-04-03 16:04:16: -- Loading Spoon: Win
2022-04-03 16:04:16: -- Loading extension: window
2022-04-03 16:04:16: -- Loading extensions: window.filter
2022-04-03 16:04:16: -- Loading extension: screen
2022-04-03 16:04:16: -- Loading Spoon: IMIndicator
2022-04-03 16:04:16: -- Loading extension: axuielement
2022-04-03 16:04:16: -- Loading extension: keycodes
2022-04-03 16:04:16: -- Loading extension: application
2022-04-03 16:04:16: -- Loading extension: canvas
2022-04-03 16:04:16: -- Loading extension: styledtext
2022-04-03 16:04:16: -- Loading extension: hotkey
2022-04-03 16:04:16: 16:04:16     hotkey: Enabled hotkey ⌘⌃SPACE
2022-04-03 16:04:16: -- Loading Spoon: CopyMarkdownToHtml
2022-04-03 16:04:16: -- Loading extension: logger
2022-04-03 16:04:16: -- Done.
2022-04-03 16:04:17: 16:04:17 CopyMarkdo: table: 0x6000023c3f40 event: windowFocused
2022-04-03 16:04:17:          CopyMarkdo: table: 0x6000023c3f40 43490
2022-04-03 16:04:20: 16:04:20 CopyMarkdo: table: 0x6000023c3f40 event: windowUnfocused
2022-04-03 16:04:20:          CopyMarkdo: table: 0x6000023c3f40 43490

[wd]

hammerspoon: Version 0.9.97 (6267) macOS: 12.3 (21E230)

[wd]

I also tested with this code, I can get the same window id. I believe this is a bug from the hammerspoon.

watcher = function(win, name, event)
  logger:i("event: " .. event)
  logger:i(win:id())
  curWin = hs.window.focusedWindow()
  logger:i(curWin:id())
end