Track length tuning

I need to tune the length of a free-hand segment. Using the track length tuning tool, it says that the length matches, but when I click on the segment after doing the tuning, the total segment length does not match the tuning length. Is this a known bug? What do I do other than try to tune this with zig-zags?

Now this is strange. I changed the tuning parameters one more time and now it seems to have made it the right length. So I guess close this one.