Gijun I'm sorry to hear you're having trouble. I'd like to reproduce this issue, but it seems that simply “copying and pasting the slider key and then undoing” doesn't reproduce the problem. Here is a video showing my test results:
Is there anything missing that might prevent us from reproducing the issue? If you’re able to reproduce the issue only in a specific Spine project file, please send us that project via email: contact@esotericsoftware.com
