After editing Report Templates, newly added columns may disappear.
This is a known issue with the Platform. Our engineers are aware of it and we will endeavor to fix the problem in a future release.
In the meantime you can use the workaround below to resolve the issue.
Please make sure you are viewing the grid in the same setting as you were when you created the report (Date of Click or Date of Conversion - this is especially important if you have conversion type columns in your report which only report in Date of Click or Date of Conversion).
If following the steps above does not resolve this issue, please contact your Support Center representative for further assistance.