Admin site are too slow for ADLDS instance at the first access.
From the QPM.UI.Admin.MVC_ADLDS log was observed that Password Manager server is looking for "PMAdmin" local group instead of "PMAdminADLDS".
"2020-11-25 00:36:24:221 I [12416:9] QPM.UI.Admin.MVC.dll AdminRequiredAttribute..cctor() >> adminGroupName = PMAdmin
2020-11-25 00:38:38:924 E [12416:9] QPM.UI.Admin.MVC.dll AdminRequiredAttribute..cctor() >> System.SystemException: The trust relationship between the primary domain and the trusted domain failed."
Create an empty local group called pmadmin with no members.