Sprite editor creates "green box" instead of a new slice

Hi all,

This seems to happen randomly to my sprite sheets after adding a random amount of slices manually or after a random amount of time.
I'm able to add new slices manually but at some point the sprite editor start creating "green boxes" that seem attached to other slices (the name of an existing slice is attached to the green box)

This is both happening in 2019.4.13f1 and 2019.4.11f

Sometimes this fixes itself by re-importing the sprite and slicing it from start (but it's only a viable solution if this happens at the beginning)

Also restarting Unity sometimes fixes the issue (I'm able to create slices again) sometimes it doesn't.

Image form this post: https://answers.unity.com/questions/1770780/cant-create-sprite-in-sprite-editor.html

 

Also deleting the slice from which the green box gets its name (and seems to be "attached" to), allows to create a new slice, but then the next attempt produces a green box again, which gets its name from another existing slice

 

Also this, that may not be related: after closing the sprite editor (by either clicking "revert" or "apply") Unity showed me a dialog to either apply or discard sprite editor changes.

 

Do you have an issue? Or are you just posting a bug?

 

I'm not sure it's an issue caused by something I'm doing wrong or if this is a bug.
Edit: my issue is that I can't work on my project because I can't any new slices

 

After much trying, I was able to fix it by using the sprite editor automatic slicing
1. Open the sprite editor
2. Pick "Slice" (top left corner of the editor)
3. "Type: automatic" and "Method: safe" (sot that the current slices don't get deleted)
4. Slice

This will create additional slice and the next time I draw them manually the green box doesn't appear

 

i had this issue in 2019.4.1f1 LTS but upgraded to 2019.4.17f1 and its fixed