In SU 2024, in a newly created and empty file, the first line (even formed from multiple edges) is not visible, only the second is visible, or if the file is not empty.
I tested in SU 2023 and 2022, and this bug is only in 2024.
Edit: It is a problem in my custom template that occurs only in SU 2024...!
The problem doesn't exist with the same template in SU 2022 or 2023... I don't understand yet...