I use the notes capability / feature to track task progress, mainly meeting details.
I have one task where the notes are very long and as I add notes to the "top section of the note" the notes / text at "the bottom section of the note" have disappeared as have the calendar and the time for the follow up timing.
The one interesting observation is that the text appears lost in the macOS version of GT but not the iOS version of GT.
PS. I deleted the two attachments to the task and the missing text reappeared. I then try to re-add the attachments and the attachments covered the text (i.e., it is as though the attachments are being displayed full size rather than the "bands" one normally sees and are covering the text. The problem is more likely related to the display of the attachments.).