Hi,
It looks like you are missing some indexes. Could you please check you have these indexes in the View_CMS_Tree_Joined view:
IX_View_CMS_Tree_Joined_ClassName_NodeSiteID_DocumentForeignKeyValue_DocumentCulture and
IX_View_CMS_Tree_Joined_NodeSiteID_DocumentCulture_NodeID? If not, you can create them (sorry for the formatting):
SET ARITHABORT ON
SET CONCAT_NULL_YIELDS_NULL ON
SET QUOTED_IDENTIFIER ON
SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
SET NUMERIC_ROUNDABORT OFF
GO
/****** Object: Index [IX_View_CMS_Tree_Joined_NodeSiteID_DocumentCulture_NodeID] Script Date: 06.12.2018 14:13:04 ******/
CREATE UNIQUE CLUSTERED INDEX [IX_View_CMS_Tree_Joined_NodeSiteID_DocumentCulture_NodeID] ON [View_CMS_Tree_Joined]
(
[NodeSiteID] ASC,
[DocumentCulture] ASC,
[NodeID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO
SET ARITHABORT ON
SET CONCAT_NULL_YIELDS_NULL ON
SET QUOTED_IDENTIFIER ON
SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
SET NUMERIC_ROUNDABORT OFF
GO
/****** Object: Index [IX_View_CMS_Tree_Joined_ClassName_NodeSiteID_DocumentForeignKeyValue_DocumentCulture] Script Date: 06.12.2018 14:13:10 ******/
CREATE NONCLUSTERED INDEX [IX_View_CMS_Tree_Joined_ClassName_NodeSiteID_DocumentForeignKeyValue_DocumentCulture] ON [View_CMS_Tree_Joined]
(
[ClassName] ASC,
[NodeSiteID] ASC,
[DocumentForeignKeyValue] ASC,
[DocumentCulture] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
GO