"Blocked by your IT admin" Samsung Galaxy 8 I'm trying to install Android Auto from apk but I get the message "Blocked by your IT admin. Unknown apps can't be installed on this device." In the last 18 months I have downloaded that app already 2x without any problems.

I have already given permission to install unknown apps from Chrome and My files. Deactivated Play Secure and any device admin apps (the only one I saw was Find my location).

I do have work e-mail app but according to my employer "Our Mobile Device Management platform (MobileIron) doesn't block any installation on your private device, as a completely separate Workspace is created and managed by us, which doesn't interfere with your private configuration".

What else can I try doing before I ask them to remove MobileIron?
Had the same issue. For me it was only fixed by disabling Google Play Store in personal profile. It wasn't easy process as it depends on Google Play services which can be disabled only after stopping Work profile. So the flow was: 1) Stop Work profile from top menu, 2) Force Stop and disable Google Play Services in Personal Profile, 3) Disable and stop Google Play Store in personal profile. After this I started Work profile again.
Hope this will help.