Unfortunately, the customization of charts has been a huge program for Crystal Reports since day 1. This aspect has received numerous complaints and I still haven't seen them respond with a decent charting control with enough customization options. It's pretty sad.

That said, one thing I wonder is if you make the modification in preview mode and then go into Design mode and immediately back into Preview mode, is your change still there? I ask this because you can make some changes to individual charts in preview mode and they will "stick" long-term. But once you make a change to the chart in design mode, then it overrides the changes made in Preview mode.

To make changes to an individual chart, go into Preview mode and right-click the chart and select Applied To This Instance. The changes you make after that will only effect that instance of the chart. Note: this is only available for changes made through the Chart Expert menu option. Other changes are always applied to all the charts. Hopefully, this might help you on your problem.

I talk about customizing charts starting on page 464 of my book Crystal Reports Encyclopedia

Yea, the charting issues are many and legion.  They plague my every waking hour.

And, yet, when I went to take a training course from BO, mostly to try to figure out what I was (I thought) doing wrong with the charts, the trainer tried to skip the charting chapter!  Apparently, most Crystal users don't use charts.  So BO doesn't commit many resources to producing a better charting tool.  So their charting tool is, to say it politely, less than ideal.  So, as a result, most Crystal users don't use charts.  I think I see an opportunity here for BO to break this cycle.  We'll see if SAP sees the same opportunity.

And, you should get Brian's book.  Because, it will answer questions for you that you never even knew to ask before.