The source code is available on github, but I do not have a direct way to contact he.
I'm going to send an issue to github.
Thanks!

I have a strange behavior when I use Spine with the software "cmd-eikana" on macOS.

"cmd-eikana" is an English/Japanese input switching software for Japanese users. (called by "⌘英かな" in Japanese)

• website https://ei-kana.appspot.com/
• github https://github.com/iMasanari/cmd-eikana

Therefore, I think there are few users who have encountered this problem, but I would like you to fix it if possible.
It may be a problem on the "cmd-eikana" side, but I have been using it for many years and have never encountered such a problem with any other software.

Example reproduction steps

• In macOS settings, go to Keyboard > Input Sources and add "Japanese > Hiragana".
• Install "cmd-eikana" from https://ei-kana.appspot.com/
• Launch "cmd-eikana"
• Launch Spine
• Open any project
• Select something in the Tree Window
• Press the left command key. Release.
• Press the right command key. Release.
• ( ↑ This operation will cause English/Japanese input switching in "cmd-eikana".)
• At this time, if you select other objects in the TreeWindow, it will become multi-selected. It's as if you're holding down the ⌘ key all the time.

This is an example of a fully reproducible procedure.
In other situations, every time you press the ⌘ key, it will always behave as if the ⌘ key is still pressed.
By the way, pressing the left ⌘ key and the right ⌘ key again fixes the problem. (If I try again, it will bug out.)

Checked Version
This bug has been occurring ever since I started using Spine about a year ago.

• 3.8.x
• 4.0.75-beta