Did the GPO actually apply?

Short answer Use gpresult to see the policies that actually reached the user and computer.

When to use it

When a linked GPO does not apply or behaves differently between users.

gpresult /r /scope computer
gpresult /r /scope user

Note

Lists applied and denied policies.

gpresult /h "$env:USERPROFILE\Desktop\GPO-Report.html" /f
gpupdate /force

Note

Keep the report for comparison.

gpupdate is not a substitute for checking OU placement, filtering and replication.