Hi Venutius,
We have tested and found no such cahce in activity feeds in our testing environment.BuddyPress Shortcodes does not create any cache elements so its not our plugin error.It works perfectly fine in our testing and development environment.
Have you enabled caching in your wp-config file?Please give us list of other plugins on your website so that we can replicate the scenario in our test environment.Also let us know the theme.Please try the error with WordPress basic theme also.