Hi, @HV
Thank you for posting in Microsoft Q&A forum.
You may check my reply in below thread to see if it helps:
https://learn.microsoft.com/en-us/answers/questions/769861/configuration-manager-can39t-connect-to-the-admini.html
And check this thread for more details:
https://social.technet.microsoft.com/Forums/en-US/b266df0d-ff99-4b41-bf5a-3114efd034d9/console-connections-configuration-manager-cant-connect-to-the-administration-service?forum=ConfigMgrCBGeneral#:~:text=In%20Sites%20%2D%20Hierarchy%20settings%20%2D%20general,on%20%22Communication%20Security%22%20tab.
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