Trouble with indentations

[NDimmick 9]

For months, I've been having trouble with rogue indentations when taking long detailed notes of lectures.   Frequently, something will trigger a change in a note that causes a hard return to alter the indentation of the preceding and following lines and the new line.  If I try to change the indent level of that line, it will affect adjacent lines, too.  If I select all the text and "Simplify Formatting," then the problem goes away for a while, but I have to redo all my indents and other rich text formatting.  The problem will come back if I paste in rich text, but it will also come back if I simply keep typing without pasting anything in from other sources.  This is driving me nuts!  

I contacted Tech Support a few months ago.  They told me to use the "Simplify Formatting" command, but this is not a good solution.  Any ideas what's going on?  Anybody else having trouble?

Evernote 6.11 (454876 App Store)

MacOS 10.12.4