I took a chance and installed the beta and it appears client VPN is busted or something under the hood changed. L2TP client VPN to my various firewall devices no longer works.
If anyone else encounters this issue and figures out a fix please post it.
I´m also facing the same problem in MacBook Air M1 while trying to connect to my workplace. Also, the same happens with my iPad Pro 2018 with iPadOS 16 - L2TP stopped working. I hope this is just a bug. I made a report with Feedback Assistant
Someone figured it out and let me know. If you use Apple Configurator to generate a VPN config and then install that profile it works. Something about creating it system settings is where the problem lives. Anyway, I'm now back on my L2TP VPN 🙂
I may have jumped the gun on "it's working" 🙁 . While I am able to connect, it looks like DNS is not working when set to use the tunnel for all traffic.
Someone figured it out and let me know. If you use Apple Configurator to generate a VPN config and then install that profile it works. Something about creating it system settings is where the problem lives. Anyway, I'm now back on my L2TP VPN 🙂