Every time I perform an action in a timeline that causes an auto save (eg. changing the importance or type of event, adding text, colour, etc.) the timeline switches from edit mode to viewing mode.
(The content that was created is still saved, so nothing is directly lost)
As far as I can tell, this only occurs for historical events, era creation and editing works as per normal.
Steps to Reproduce
Perform any action in a timeline while in edit mode.