Additional features, settings, or issues not covered by specific Microsoft Teams categories
I have raised Microsoft ticket for the issue and got reply like this "We would like to provide an update regarding the issue where Teams Desktop and Teams on the Web may freeze when users access Contacts (People App).
Microsoft has confirmed that this is a known issue and has identified a fix. The fix is currently being deployed through the Teams service update rings.
The fix is expected to reach Worldwide (General Ring) customers by the first week of September."