I've used PPT 2013 for reporting for a few years, and had a similar process with previous versions. This problem has only just started about 4 weeks ago. I'll simplify this as much as I can.

Basic process is to create a chart in Excel 2013, using data within a charts workbook. Do as much formatting as makes sense, but Powerpoint doesn't always use the formatting that's brought across and there are usually some tweaks needed.

I 'copy' the chart in Excel, and paste into the PPT slide using "Keep Source Formatting and Link Data". Repeat for as many different slides as needed. The Excel workbook is in the same directory as the PPT file. To send to the client, I break the links using Edit Links (manually because the FixLinks tool won't break these kinds of links and I haven't found another tool - I'm not good with VB), then save the PPT file with a different name so that I can distinguish internal and client versions.

This process has worked pretty well for several years. There have been occasional glitches when the PPT has somehow got charts messed up, but I've usually found that there was a mistake in following the process, or that redoing a couple of slides fixes the issue.

But with this report, the charts for several of the slides get messed up, with subsequent slides that are based on the same original data - but use different tabs in Excel with copies of data - looking somewhat like the first. After the links were broken, and when I had closed Excel and PPT and then reopened PPT. So if the first chart showed bars for A1/A2/A3 and the next slide used B1/B2/B3, the problem would be that the next slide looked as though it was showing A1/A2/A3.



I found a couple of threads that mentioned problems with PPT 2013 and/or PPT 2016 that looks like same issue - when duplicating slides with charts in the data gets messed up. The symptoms weren't exactly the same, but similar enough to make me revise the process. There's a video at https://www.youtube.com/watch?v=u14zxHTjzOs

I've been asking myself what's changed and what's stayed the same since this was working OK.

1. I'm now on Windows 10. It was originally set to automatically update Office as well as Windows, and I discovered a lot of update. But having reinstalled Office 2013 after changing the update setting, and finding the same issue, I don't think that's the problem. And I've tried it on a backup machine (also Windows 10) with a new Office 2013 installation.
   
2. I use filtering to adjust the data being shown in the chart - within PPT. I don't think that's the issue because I've been using the same technique since I found it in Office 2013 and previous reports didn't have this problem. Each Excel tab has a copy of the data for one set of bars, and a copy of the chart.
   
3. The slides with the problems all use a technique I recently found to allow formatting of axis labels. The starting point is at https://peltiertech.com/individual-format-category-axis-labels/ It's possible that this is involved in the issue so I'm going to take another look, and perhaps eliminate it for this current urgent issue.
4. The Excel tabs with the copies all have a second series that is from a single tab within the charts workbook. I just noticed this (previous efforts at fixing were aimed in different directions), so I'll review.

However, when all is said and done, there appears to be some underlying issue of links that aren't broken as they are supposed to be. I use a virtual drive for reporting and supporting files (created with SUBST), so it is easy to see that the problems exist. Once the file has been saved as one that supposedly has the links broken, it no long matches the file with links. I now suspect that the act of breaking the links is what causes the problem.


I'm sorry for the long message, and would appreciate any insights and advice.


Thanks
Mike