Origin Ver. and Service Release (Select Help-->About Origin): Origin 2020b Operating System: Windows 11
I plotted my data as a line plot and it looks good except a line is connecting the last point with some point in the middle. I have 9000 points, so it would be tedious to look through all of my data. When I plot the data in excel, this extra line does not appear. I also tried sorting the x values from lowest to highest in excel before moving to origin and this did not fix the issue either.
You can turn on Sparklines for your X column and see there is a drop.
Select X column, and from the popup mini toolbar, find the Sparklines button to turn it on. You can then double-click that sparkline image and use Data Reader to find the drop happens at row 9001, from 100 to drop to 55.02
Is there a reason you are not using the latest version (2022)? Your version may not have the mini toolbar buttons to turn on sparklines.