SpiderOak One and Groups used to have a setting in the preferences for flap control. This setting proved to be less useful than hoped and so was removed in version 6.3.0. If you see the option, that probably means are on an old version and should upgrade to the current version of SpiderOak One or Groups.
If you previously enabled it, the option will continue to appear. We encourage you to disable it, which will cause the option to disappear from the GUI.
For your background information, flap control was intended to mitigate the effects of having improperly selected for backup frequently changing system or application data. Users found that the control was less helpful than simply deselecting the offending data (which shouldn't be selected for backup in any case). For this reason, we encourage all users to follow our best practices as given in What Data to Select for Backup.