toeto Thank you for submitting your Spine project!
Regarding the first problem, since you have disabled Auto Key, when you hide the attachment in this state, the color of the key next to the slot will only change to orange and the key will not change until you press the Key button. Also, when you restore visibility, the color of the key returns to its original color. This is the expected behavior.
However, it is confusing that once the key color changes to orange, the orange color remains while the timeline bar is scrubbed. I think this is something that should be fixed, so I will create an issue ticket for this later.
(If this is not the problem you are having, please let me know.)
Regarding the second problem, while checking your Spine project while organizing it a bit, the following error was displayed:
Was this Spine project originally created with an older version and reopened with 4.2? In rare cases, there may be a problem with data created in an older version of Spine that is corrected when opened in a newer version of Spine. In this case, rather than a bug in 4.2.36, there may have been a potential problem with the original data. I haven't reviewed it thoroughly yet, but if this Spine project is an upgrade from an older version, and if you still have the older version of the Spine project, it would be helpful if you could send it to us as well.
