Teams completely freezes after clicking on Contacts.

I would focus on the local Teams desktop cache and client version. First quit Teams completely from the system tray, then restart Windows and update Teams from the app menu or Microsoft Store if that version is Store-managed. If it still freezes only on Contacts, reset the Teams app from Windows Settings > Apps > Installed apps > Microsoft Teams > Advanced options > Repair, then try Reset if Repair does not help. Also test with the new Teams client profile after signing out and back in. If your organization manages Teams, send the admin the Teams version, Windows build, and confirmation that web works while desktop freezes.