CU7 applied.
Designer Dashboards - Scheduled views being emailed only show logon page instead of the dashboard.
Release : 20.4 CU7
defect (DE566127)
This is being investigated as a defect in CU7.
As a workaround, you can deploy ump_dashboard 20.46 (attached to this KB.)
This fix will be available in the CU8 release which is tentative to release by the end of this month (June/2023).