Thanks SiZiIOUS for the link - eventually that led me to try testing for null references - it seems that during the redirect from HTTP to HTTPS at least some part of the COM object is "lost".
After resetting things back to defaults (including Internet Zone security settings), it appears that the two things I need to do to get this to work without running PowerShell as administrator are:
- Disable IE Enhanced Security Configuration
- Add the desired URL to Compatibility View
Also worth noting - if after this I add the URL to Trusted Sites, it actually stops working again, which I suspect caused me to miss the solution at some point previously since when I tried this combination of settings it was probably listed in Trusted Sites. Why that would be, I'm not sure, but maybe it will spark a thought for someone who can explain.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…