Remove side snapping when editing in sleep graph

Detailed description of the problem:
When highlighting in the sleep graph, the edit line frustratingly snaps to the sides of the graph. Every morning I look at my graph to approximate and manually log in a note the time between when I fell asleep and when I woke up, so I try to highlight that time period abd it should tell me the length that I slept at the top. However, I always want to place the highlight cursors precisely within this snapping threshold, so I can never place it accurately enough. No snap at all would be soo appreciated!

Steps to reproduce:
Open previous night’s sleep graph, drag over the graph to highlight and move each end towards the sides.

Version of Sleep as Android: