Slow performance in MMC when showing all possible attributes (4379738)

When viewing Advanced Properties on a user, and then selecting "Show all possible attributes" this causes the service to load for a good number of seconds until it eventually loads the entire list.

Due to numerous factors, it is expected there will be a delay when opening "Show all possible attributes" under the Advanced Properties of a user. Please see below for more information on the factors that may impact the load time.

The time to load all properties of an object in Active Roles, is dependant on how the account is configured, IE:

• Local AD object with no mail
• Local AD object with an local mail account
• Hybrid AD object with no mail
• Hybrid AD object with an remote mail account

The time impact depends on:

• Number of virtual attributes, therefore SQL performance
• If a hybrid user, the performance of MS Graph to returned the properties, or for any cached information to be refreshed as required
• If the object has a local mail account, the availability and performance of the Exchange Servers Active Roles needs to communicate with to retrieve the values
• If the object has a remote mail account, the availability and performance of  MS Graph and/or Exchange Online cmdlets to communicate with to retrieve the values

And more, like any impact from certificate authentication, IE any delays maybe due to validation of the certificate etc.

See also KB4340870.