See the attached png image to see what I am talking about.
First, what does the yellow bar on the left hand side of the code editor mean?
Second, why does line 52 show vertical indentation lines when there are no spaces or tabs on that line?
The yellow bar indicates that there are changes, that have not yet been saved. It turns green after saving.
By the way you can jump to the next changed place with Ctrl+F3 or the previous one with Ctrl+Shift+F3 or via "Search" menu
If you don't like this feature, you can switch it off by unchecking "Settings -> Editor -> Margins and caret -> Left margin -> Use changebar".
Are you sure there are no spaces or tabs ?
If yes, you found a bug in scintilla.