Snap failures lead shape to be trimmed

If you click the "snap" button in the shape view, if any part of the route fails to snap, everything in the shape after that point is deleted. For instance, in the example below, the first part follows roads and the second part goes off-road; attempting to snap destroys the latter part of the route. This is an extreme example but I've seen this behavior quite a few times where one point lands on the wrong side of a dual carriageway, etc - see this video for an example.

I suspect this is an upstream issue with the Mapbox map-matching service, but a workaround might be to compare the ends of the snapped shape to the original shape, and if they aren't nearby issue an error or warning, or maybe only replace part of the original shape with the snapped shape. Having the ability to undo snapping would also help.

Firefox 152.0.1 on macOS 26.5.1