Microsoft has made a recent update around Aug 2023, which affects the way links in Outlook and Teams are opened within these applications. Previously, the default browser setting determined how links were opened, but now they are controlled within the individual applications, with the default set to Edge.
To change how links open from Outlook and Teams you need to change this setting in the application.
More info here:
https://learn.microsoft.com/en-us/outlook/troubleshoot/message-body/view-emails-and-web-links-in-browser
https://support.microsoft.com/en-au/topic/web-links-from-outlook-emails-and-teams-chats-open-in-microsoft-edge-b0e1a1c1-bd62-462c-9ed5-5938b9c649f0#:~:text=If%20you%20want%20to%20turn,Open%20hyperlinks%20from%20Outlook%20in