Lines in wall corners in 2d

[Daria_arch]

Hi,
How can I get rid of the lines in the corners of the walls in the plans? These lines are visible when opening in pdf, and are very noticeable.

Operating system used: Windows 25

[Lingwisyer]

Are you printing as PDF or exporting using the inbuilt PDF function from the Publisher?

[Daria_arch]

I have this no matter how I save the drawing, through a publisher or simply saving the layout as  PDF....