Hi ImmunoWalnut,
Thank you for reaching Microsoft Community. I'm sorry to hear about the freezing issues you are having on your Surface Pro 8. Definitely, this is not the experience we want you to have.
When the screen freezes after you log in, will it show your desktop screen or just a black screen?
Did this issue started immediately when you first got the device or this just started recently?
Please run these steps first on your Surface Pro 8 then see if it helps:
1: Run Surface Diagnostic Toolkit
See: Fix common Surface problems using the Surface Diagnostic Toolkit (microsoft.com)
2: Check for Windows Update
Go to Windows Settings > Update & Security and select Check for updates
Make sure all updates need are installed including Optional updates
3: Update drivers and firmware
Check what is the current OS Build of your Windows version by going to Settings > System > About.
Go to Download driver and firmware for Surface, choose Surface Pro
Then click the link next to Surface Pro 8 then click Download on the next page.
Choose the .msi file that matches your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
4: Run System File Checker Tool
See: Using System File Checker in Windows (microsoft.com)
Hope this helps.
kind regards,
Marrion