BuddyPress.org

Caching issue.

Most likely, you implemented server side caching in your site. When you open the page, the cache responds so the request does not hit the server. Disable page cache in your site and check again.

The other possible reason is browser cache, which you can obviously check by loading the page in another browser or reloading the page with a URL paramter like thispage.com/members?random_parameter this forces browser to reload the page form the server.