So when I am drawing lines on layout occasionally there is an issue where lines jump to random locations (normally where they were referenced to) when I am trying to edit the lines:
There is an issue that I have been reporting to the SketchUp team where the centre snap of an object can hijack other snaps or locations where you want to end an operation when close to the centre snap.
This kind of bug happened to me a few days ago in 2024, and it does seem to still be happening in 2025. The workaround is to cut up the segments into individual lines, move them, and then glue them back together when they are where you want them - a process now much easier in 2025 with the new cut/glue (explode/weld) feature.