Hello Joel, I am Henry and I want to share my insight about your issue.
The issue appears to stem from a configuration or policy deployed through Intune on Autopilot devices, which doesn't exist on your AD-joined machines.
To confirm it's a policy issue, perform this test:
- Create a new, empty configuration profile in Intune.
- Create a new security group and add one or two affected users/devices to it.
- Exclude this group from your primary security baselines, ASR rules, and Defender policies.
- Sync the test devices and reboot.
- Ask the user to test performance.
If performance dramatically improves, you have confirmed the issue lies within your security policies. You can then add the policies back one by one to find the specific setting causing the slowdown.
Hope this points you in the right direction for troubleshooting.