When asking something technical like this you should probably link the map in question. This is the map:
beatmapsets/2428136#osu/5286690tldr; Even if you have grid snap off, hitobjects are always placed on an invisible grid which leads to the mentioned inconsistencies when using low distance snapping.
The issue stems from the fact that hitobjects have integer coordinates from (0,0) to (512,384). When distance snapping, the object is placed not placed on the perfect circle that is shown, but instead pushed a bit away onto this invisible 512x384 grid. For high distance snapping this works fine, since higher snapping distance = bigger circle = more coordinates in the grid that are close to the circle; so it feels more smooth and we are likelier to get the distance snap we wanted.
When the distance snap is small, like in your map, this becomes more noticeable.
There is no real fix to this. In lazer editor this is much less of an issue, as coordinates have two decimals, however submitting a beatmap via lazer leads to the coordinates being rounded to the nearest integer (I assume for backwards-compatibility), so the problem pops up again.
