We use rich text fields a lot. For wiki documents, to create content, notes, etc.
I was typing for quite a long time. By accident, I removed the text.
The text was not in the activity log. I think because I was typing the whole time without ‘leaving’ the rich text field.
Is this how version history works? Or should the text be auto saved after x period?
If you make a change and realise it’s a mistake, normally Ctrl-Z will undo, but this depends on you not navigating away.
There is no fixed auto-save period, but Fibery creates a new entry in the version history when it is determined that the state has been stable for a while (i.e. no changes by a given author for a few minutes).
If you keep making lots of little changes (including adding/changing/deleting) in quick succession, then they are pretty much treated as a single edit.
That was the case and therefor Ctrl-Z didn’t worked 
So if you create a new entity (a concept for a blog for example) and you type for 30 minutes straight in the rich text field, then that text will not be saved?
An entry in the version history will be created when you’re done typing.
Not every key stroke during the 30 minutes will be captured though.
If you type ‘XYZ’, delete it and then type ‘ABC’, there will likely be no record of ‘XYZ’, only that you ended up typing ‘ABC’.
That’s never the case (I think?).
The problem occurs when you type a lot of text, without a longer pause. In my case I lost a lot of work because there was no auto save at all. Since I was typing without leaving the rich text field box.
I was expecting an auto save after x period (every minute or so?) so that you can never loose that much work. But that’s not how it works if I understand you correctly?
You understand correctly. There is no ‘autosave’.