I've previously reported this same issue, and I understood it was meant to be fixed by a patch.

We make use of the Notes feature to share internal info among our support team.

In some cases - if you need to Edit an existing note - the Add Note window pops-up - but the existing content is gone.

I'm not sure if this could be related to the content itself (application log entries with non-alphanumeric characters), or if it is text formatting related (e.g. retaining formatting from the application it is being copied in from)