I just wrote a discussion topic and chose the preview screen to check it before posting. I closed the preview and reopened my tab where I had written the discussion. It was completely empty.
I completely rewrote the discussion and previewed it again to check for mistakes (the pale yellow background and very small light grey font in the entry window is terrible for those who need glasses). I saw something I wanted to change when the nice black on white preview appeared in a new tab.
This time I decided to be smart and not close the preview tab in case I needed to copy the text if a problem arose. To my chagrin the add discussion tab was empty again and so was the preview when I returned. I am writing from an iPad with latest iOS version. I wonder why preview deletes the text in the original add discussion page and why leaving the preview pane reverts that tab to a blank text entry screen on iOS devices.
I just tested this on my old MacBook and it works fine. It also has a Decent Text Entry background color and font. We have iOS issues to resolve and the same low contrast screen is the default on any comment or post. Even if we don't solve the disappearing text I hope we can dump the poor text entry/editing screen. Anything besides white on light pink would be an improvement. If I can read what I typed I can live without the preview function.
Ironically, this discussion was in general discussions, about "How to Get Help" and reminding members to use the Technical HELP discussion category. I also had satisfaction questions to see what users felt if they had used technical help. After that I ended up losing it twice and posting a new actual help request.