All the wall cleanups looked fine when you closed the drawing. But when you reopen the drawing, there are solution tip icons being displayed.
Under some circumstances, the order in which walls are cleaned up affects the display.
When troubleshooting this condition, select the walls in question, and double-click one of them. On the Properties palette, select No for Cleanup automatically, and then select Yes. Try this on different walls to see whether you can locate the unstable wall. Usually, adjusting the justification line of the unstable wall fixes this problem.