Can't set as delegates for some users in Microsoft 365 Admin Center

[SteinerSupportCalvary]

Our Setup is Active Directory syncing to Office 365 using Azure AD Connect.

Here's an interesting problem. I have certain users that I need to setup as delegates for Room Resources so they can help manage room calendars. However in the Microsoft 365 Admin Center, some of the users I need to select don't show up as selectable delegates (same if I try to select them as delegates for other users). If I'm in the exchange admin center, I can select them as deleages for other users without issue, however exchange admin center won't allow me to set a deleate for a room resource, it just tells me to do it in Microsoft 365 Admin Center. Any thoughts on how I can fix this?

[#2]

Sounds like a permission issue? Were you able to review this article in your research?

https://docs.microsoft.com/en-us/exchange/permissions-exo/permissions-exo

[#3 · Accepted solution]

I'd recommend avoiding the O365 portal where possible, it's ridden with bugs. To add a resource delegate via the EAC, go to Recipients -> Resources -> Double-click the room in question -> Booking delegates -> add the person.

To do it via PowerShell: 

Set-CalendarProcessing bathroom -ResourceDelegates user@domain.com

[#4]

@Vasil Michev Totally agree, however when I attempt to make the change through EAC it doesn't bring up a way to select a delegate for the resource, but instead brings up a tip that says "On the properties page for this room, you can specify who can automatically reserve the room without approval and who can request owner approval to override existing reservations." This doesn't happen with users, only with Resources. This is included in case anyone else comes across this post and has similar issues. I was able to add the needed users using a similar powershell command. 

@Don Fernandes I agree that it is likely a permissions thing. Before posting I spent a few hours trying to find a permission that could cause this kind of peculiar behavior (where some users are only not selectable as delegates in M365/O365 Admin Center but are selectable via any other means). I think it comes down to the Admin Centers long history of being a little janky. On review I didn't find anything that stuck out in that link but I appriciate your help.

[#5]

I had the same issue but with delegating access to a user on another person's acct. I couldn't see the person I was trying to delegate access to and I figured out that it was because the user acct had previously been converted to a shared acct - once I converted it back to a regular acct I was then able to find and delegate this access to that user.