Weired edge decoration

After the update (zypper up) today, as shown in following url, I find the edge of my task bar exhibiting a white line.

Same exhibition also display on the edge of manual launched by pressing the meta key.
I don’t recall I had this edge decoration before.
Is it possible to remove it?

I am running on KDE.

I am not seeing that here (testing in a VM). However, you appear to be using a different theme, so perhaps this isn’t a good comparison.

Is your picture of the complete, or only part of the screen?

I ask, because if I go into edit mode on the task bar, and close the “more options” part at the bottom, there is still some sort of edit panel showing at the top of the screen. And I do see a line on the task bar until I close that panel at the top.

Thank you for the reply, and sorry for my late respond.
As you can see in the snapshot (SUSE Paste), I have completed out of the edit mode, and the white line is still there.
Very strange :|…

Try a different user. still broke??