I see differences too but now as much as you. I suspect the cursor position is calculated from the data yet the total ascent listed at the bottom is the result of in-watch calculations. On thing to check is if you've got the auto altitude data correction enabled. See if that helps the situation.

I've noted before the the watch's displayed average speed differs a little from what the software reports and I always put that down to the watch doing "simple" math during the ride and maybe not being so accurate.