Thanks for providing the version info. Please note that you are using an old version of the spine-unity 4.0 runtime, the latest available version is 4.0 2022-09-26, available for download here:
https://esotericsoftware.com/spine-unity-download#spine-unity-unitypackages
If you are in the starting phase of your Unity project, we would strongly recommend using the latest version of Spine and the spine-unity runtime, which is 4.1.
If the problem persists, could you please share the exported assets or a minimal Unity project which still shows the problem? You can send it as a zip package to contact@esotericsoftware.com, briefly mentioning this forum thread URL so that we know the context.