Persistence of registration lists for previous recurring meetings after updating recurrence timespan

[pflagpdx]

I edited All Occurrences of a couple of recurring meetings to extend the timespan. When I went back to view my list of previous meetings, the most recent ones disappeared and the registration list was not accessible.

Apparently there is not a way to extend a recurrence without destroying information about a past meeting that was part of that recurrence.

Is this correct, or can I recover that information, and what is the proper way to do what I wanted to do?

Thanks.