Hello,
We've had the same problem and were able to figure out the cause.
If you go to "Components" > "Preferences" > the tab "Projects & Analyses", then there is a checkbox "Make date range components relative to panel calendar by default".
Any panel that is created by a user that has this setting enabled, will have this issue.
So to fix this issue for existing panels: disable this setting, and then rebuild the panels where this issue occurs. You can not "duplicate panel" because the new panel will have the same issue. You can create a new panel and then "copy visualization" from the broken panel to the new panel.
@jennifer_dungan For recreation purposes: Enable the setting described above, and create a new panel in a workspace. Then add a metric as a column, and you should find that you are not able to right click the metric. You will also notice an error in the developer tools' console window when you click it.
Kind regards,
Sam Van Renterghem