A few days ago[0] I was writing a Jira ticket after hitting the "Create" button and I wrote the description (the body of the ticket) for ~30 minutes. I switched the ticket type from A to B (no epics involved) and it wiped out the entire description. All I did was select a different item in a select drop down box provided by the form's UI.
There was no warning it would clear the description and no draft saved. I lost 30 minutes of work.
I normally manually copy textareas every few minutes on any Atlassian page because I don't trust their site (to be fair I do this for most sites too) but in the above case I had just copied a link reference which overwrote my clipboard. At the time I also didn't have a multi-clipboard tool installed since it was using a company issued machine that I don't have tricked out yet.
[0]: https://twitter.com/nickjanetakis/status/1540353527859466246