Index: src/bp-groups/bp-groups-template.php
===================================================================
--- src/bp-groups/bp-groups-template.php
+++ src/bp-groups/bp-groups-template.php
@@ -4358,7 +4358,7 @@
 	}
 
 	$template_names = array(
-		'groups/single/front-id-'     . sanitize_file_name( $group->id )     . '.php',
+		'groups/single/front-id-'     . (int) $group->id . '.php',
 		'groups/single/front-slug-'   . sanitize_file_name( $group->slug )   . '.php',
 	);
 
Index: src/bp-groups/classes/class-bp-groups-theme-compat.php
===================================================================
--- src/bp-groups/classes/class-bp-groups-theme-compat.php
+++ src/bp-groups/classes/class-bp-groups-theme-compat.php
@@ -223,7 +223,7 @@
 		 * @param array $value Array of default template files to use.
 		 */
 		$new_templates = apply_filters( 'bp_template_hierarchy_groups_single_item', array(
-			'groups/single/index-id-'     . sanitize_file_name( bp_get_current_group_id() )   . '.php',
+			'groups/single/index-id-'     . (int) bp_get_current_group_id()                   . '.php',
 			'groups/single/index-slug-'   . sanitize_file_name( bp_get_current_group_slug() ) . '.php',
 			'groups/single/index-action-' . sanitize_file_name( bp_current_action() )         . '.php',
 			'groups/single/index-status-' . sanitize_file_name( $group->status )              . '.php',
Index: src/bp-members/bp-members-template.php
===================================================================
--- src/bp-members/bp-members-template.php
+++ src/bp-members/bp-members-template.php
@@ -1423,7 +1423,7 @@
 
 	// Init the hierarchy
 	$template_names = array(
-		'members/single/front-id-' . sanitize_file_name( $displayed_user->id ) . '.php',
+		'members/single/front-id-' . (int) $displayed_user->id . '.php',
 		'members/single/front-nicename-' . sanitize_file_name( $displayed_user->userdata->user_nicename ) . '.php',
 	);
 
Index: src/bp-members/classes/class-bp-members-theme-compat.php
===================================================================
--- src/bp-members/classes/class-bp-members-theme-compat.php
+++ src/bp-members/classes/class-bp-members-theme-compat.php
@@ -170,7 +170,7 @@
 		 * @param array $value Array of template paths to add to hierarchy.
 		 */
 		$new_templates = apply_filters( 'bp_template_hierarchy_members_single_item', array(
-			'members/single/index-id-'        . sanitize_file_name( bp_displayed_user_id() ) . '.php',
+			'members/single/index-id-'        . (int) bp_displayed_user_id()                 . '.php',
 			'members/single/index-nicename-'  . sanitize_file_name( $user_nicename )         . '.php',
 			'members/single/index-action-'    . sanitize_file_name( bp_current_action() )    . '.php',
 			'members/single/index-component-' . sanitize_file_name( bp_current_component() ) . '.php',
Index: src/bp-templates/bp-nouveau/includes/groups/functions.php
===================================================================
--- src/bp-templates/bp-nouveau/includes/groups/functions.php
+++ src/bp-templates/bp-nouveau/includes/groups/functions.php
@@ -940,7 +940,7 @@
 	// Use a global to avoid requesting the hierarchy for each template
 	if ( ! isset( $bp_nouveau->groups->current_group_hierarchy ) ) {
 		$bp_nouveau->groups->current_group_hierarchy = array(
-			'groups/single/%s-id-' . sanitize_file_name( $current_group->id ) . '.php',
+			'groups/single/%s-id-' . (int) $current_group->id                     . '.php',
 			'groups/single/%s-slug-' . sanitize_file_name( $current_group->slug ) . '.php',
 		);
 
Index: src/bp-templates/bp-nouveau/includes/members/functions.php
===================================================================
--- src/bp-templates/bp-nouveau/includes/members/functions.php
+++ src/bp-templates/bp-nouveau/includes/members/functions.php
@@ -264,7 +264,7 @@
 	// Use a global to avoid requesting the hierarchy for each template
 	if ( ! isset( $bp_nouveau->members->displayed_user_hierarchy ) ) {
 		$bp_nouveau->members->displayed_user_hierarchy = array(
-			'members/single/%s-id-' . sanitize_file_name( $displayed_user->id ) . '.php',
+			'members/single/%s-id-' . (int) $displayed_user->id . '.php',
 			'members/single/%s-nicename-' . sanitize_file_name( $displayed_user->userdata->user_nicename ) . '.php',
 		);