Creating RDS Virtual Desktops failed with no error

Hello guys.

From unknown time on production farm creating a pool collection start failed with no error.
https://prnt.sc/pwddy1

Hosts Hyper-v servers in Failover Cluster with CSV. HA configured with database on remote mssql server. Error comes out right after exporting template.Howeverthe template appears in the selectedfor exporting directory.

CB,Hosts - windows server 2016 with last updates.

Template - i tryied several, even with templated which works in another pool.Windows10pro1806,Windows10pro1903

On CB rdms-ui-operational says, that collection created successfully https://prnt.sc/pwfv57

rdms-ui-admin says, that collection creation failed https://prnt.sc/pwfvqa

on vm-host export was successfull https://prnt.sc/pwfxkn

C:\Windows\System32\tssesdir\*.xml there is no job associated with this task

https://support.microsoft.com/en-sg/help/2747656/introduction-to-log-files-that-are-useful-for-troubleshooting-rds-issu

doesnt not help, no such file on connection broker even after add reg params

IN CB Databases i have some more interesting picture:

SELECT *
  FROM [DBCBSRV].[rds].[Pool]

gives https://prnt.sc/pwg294 , where vdi3 is pool, but it works normally.

SELECT *
  FROM [DBCBSRV].[rds].[ErrorLog]
  WHERE DATEADD(dd, 0, DATEDIFF(dd, 0, TimeStamp)) = DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE()))

gives https://prnt.sc/pwg48n

any suggestions?