This is related to SPR# KSAUD5XHN8
Delegation provided via administrator assumes [AccessContacts] role granted
A] In Mail template 12.0.1 below was the issue.
Domino Administrator is added into LocalDomainAdmin group. This group is added into the ACL of the other users with user type PersonGroup and Manager access.
When Domino Administrator tries to add user into Access and Delegation, user are getting added, but when check backed again, delegated user are not shown in the list.
Steps to reproduce are as below.
1) Add Domino Administrator into LocalDomainAdmin group.
2) Let's say for UserA ACL, add the LocalDomainAdmin group with Person Group and Manager Access.
3) Now from Domino Administrator open the mail database for UserA. From Preferences >> Access and Delegation try to add another user let's say UserB.
4) It does show the UserB name. However when we click Ok and again check Access and Delegation, UserB is not shown in the list.
5) If Domino Administrator is listed in UserA ACL individually with user type Person and Manager access, then able to add users in Access and Delegation successfully.
Reference Article: https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0099716
B] This issue was fixed in 12.0.2 mail template.
C] The code of the 12.0.2 mail template checks the access level of Administrator and considers the "[AccessContacts]" role is same as Owner of the mail file has.