Page/frame border missing corner notch

Hi, I’m trying to create a 9pt page border (and/or frame border) with LibreOffice Writer 6, however, as you can see in the screenshot below the border is incomplete. LO doesn’t render the corner join in Writer and it isn’t there when printed or exported to PDF either.

This is only affecting the border applied to a page or a frame that was insterted interactively, table borders and inserted text frames are complete. Is there a setting I’m missing to get the border joined or is this a bug in LO?

This error occurs with every line size above the smallest (I think it may still occur then, but it is too small to tell). For whatever reason the left and bottom borders do not touch… ever. Weird.

It’s an old problem (on 5.4 was even worst) that’s fixed on 6.1

Bug 81643 - Borders are drawn as rectangles and so they are not joined well at the corners