I've noticed since updating to 2.9 that snapping seems to be more tempromental compared to older versions. I'm finding in editing now, that snapping sometimes won't work when I'm trying to snap from one line feature to another.
When this happens, I just need to hit <ESC> and retry and usually it works, if not I just may need to move the end point of the line close by, commit it and then try and re-snap and is works.
Not sure if it's something others have found when editing in ArcGIS Pro 2.9 at all or not?