I've been investigating why the text editor wasn't honouring carriage returns so any text entered ended up in one long line.
I've made some changes to the configuration file for the editor and it now seems to work ok. As a result, I've enabled the WSYWYG editor again (more features than the 'simple' editor')
After the last software upgrade, it looks like I'd overwritten the changes I'd made to the editor config. I've changed it back to honour carriage returns but I also note that SHIFT+ENTER forces a new line which might help.