For instance, I'll enter 4 lines and scroll through to review. As I go, it duplicates prior lines and will add them to the bottom of the sheet.
I had this same issue too. Some kind of glitch due to scrolling.
I now don't scroll, but just use my arrow keys to navigate back through the journal entry. Or I use the Tab button to move to the next field, or Shift & Tab to move to the prior field.
Using my keyboard to navigate through the journal entry is the only way I've been able to prevent the lines from duplicating and/or skewing my entry.
*Community Hub is the new name for Sage City