Thank you for your detailed report. Apparently, when a mesh is bound to a bone other than its parent, it has a strange effect on the rotation and translation of the bound mesh. You wrote that the image goes "disappear", but it might be still in the viewport, just hidden somewhere. We will investigate and fix this issue immediately, but in the meantime, we would appreciate it if you could use 4.0.56.
I created an issue for this on GitHub:
https://github.com/EsotericSoftware/spine-editor/issues/624
We've fixed the binding problem in 4.0.58 and it has been released. Please update your Spine editor and check if the issue is solved.
