Please note that Mac users at HSC who formerly attended another university or trade school sometimes see their old institution's login screen when trying to sign into their HSC webmail. This is due to a browser issue that can affect all the user's browsers.
Try this to fix it:
https://blogs.chapman.edu/information-systems/2020/12/01/how-to-disable-cross-site-tracking-on-your-internet-browser/
Cross-site tracking services can be disabled on all major browsers by following the steps below:
Important Note: Disabling Cross-Site Tracking could prevent you from downloading images and files in Canvas and other sites.