correct url param for started and upcoming milestones

ee/app/assets/javascripts/boards/stores/boards_store_ee.js

@@ -43,7 +43,7 @@ class BoardsStoreEE {
       if (this.store.boardConfig.milestoneId === 0) {
         milestoneTitle = 'No+Milestone';
       }
-      updateFilterPath('milestone_title', milestoneTitle);
+      updateFilterPath('milestone_title', encodeURIComponent(milestoneTitle));
       this.store.cantEdit.push('milestone');
     }
 

ee/app/helpers/ee/boards_helper.rb

@@ -9,8 +9,13 @@ module EE
                                 (!@project.feature_available?(:multiple_issue_boards) ||
                                  !@project.feature_available?(:scoped_issue_board) ||
                                  !@project.feature_available?(:issue_board_focus_mode))).to_s
+
+      milestone_title = board&.milestone&.title
+      if [::Milestone::Started, ::Milestone::Upcoming].include? board&.milestone
+        milestone_title = board&.milestone&.name
+      end
       data = {
-        board_milestone_title: board&.milestone&.title,
+        board_milestone_title: milestone_title,
         board_milestone_id: board&.milestone_id,
         board_assignee_username: board&.assignee&.username,
         label_ids: board&.label_ids,