Index: src/bp-templates/bp-legacy/js/buddypress.js
===================================================================
--- src/bp-templates/bp-legacy/js/buddypress.js
+++ src/bp-templates/bp-legacy/js/buddypress.js
@@ -1739,6 +1739,12 @@
 
 /* Setup activity scope and filter based on the current cookie settings. */
 function bp_init_activity() {
+	// Remove the 'oldestpage' cookie to start fresh.
+	jq.removeCookie('bp-activity-oldestpage', {
+		path: '/',
+		secure: ( 'https:' === window.location.protocol )
+	});
+
 	if ( undefined !== jq.cookie('bp-activity-filter') && jq('#activity-filter-select').length ) {
 		jq('#activity-filter-select select option[value="' + jq.cookie('bp-activity-filter') + '"]').prop( 'selected', true );
 	}