I understand your frustration. It seems like you've done everything correctly, but the VPN connection is still not working on your new Windows 11 laptop. Here are some potential solutions that might help:
Some users have confirmed that reinstalling network adapter devices makes a difference.
Turning firewalls off, this can also feasibly resolve this annoying problem.
Check the log files in the VPN server and in Windows, this might give you more information about what's causing the issue.
Update your Network Driver, this has helped some users resolve the issue.
Enable MS-CHAP v2 in VPN properties, this has resolved similar issues for some users.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.