I tried emailing this to support@hubitat.com a few times now, but maybe they don't monitor that inbox anymore.
See the below OneDrive link for a screen recording to demonstrate my below findings.
I'm running a C-5 with Platform Version 2.4.0.144
HSM Issues.mp4
You might need to download the video or change it to 1080p in order to see it clearly.
Delay intrusion alerts only for these doors
It appears that HSM is not working correctly for Delay Alerts when selecting individual doors.
Alert Cancel with Pending Alert disables Future Alerts
Also I noticed that if you cancel an HSM Alert while you have a Pending HSM Alert that you will get no future HSM Alerts until you Disarm and Re-arm the System.
This seems like it could be a pretty big deal as there is the potential that an HSM Alert is Auto-Cancelled by a Rule while there is a Pending Alert effectively disabling your HSM from issuing any further alerts without user interaction.