NetBird now includes a built-in reverse proxy directly in the management server. Point a custom domain at your NetBird server, configure the proxy in the dashboard, and your internal services are securely accessible from any browser, no VPN client required for end users.
You can also use profiles and set management URL in the settings through the UI. You can even switch between self hosted and cloud versions: https://docs.netbird.io/client/profiles
Would you mind sharing more about the issue? We have enterprises running NetBird with thousands of users with near zero issues. Apparently it is usually other way around - people migrating from Twingate to NetBird because of the former solution instability. Well, that is from our experience.
I suggest trying NetBird cloud to eliminate a potential misconfiguration of the self-hosted instance.
Defguard as of my knowledge is a traditional VPN with a central gateway. NetBird is an overlay network with a full mesh capabilities. Though you can set it up in a gateway-like style with NetBird Networks but without opening ports and with HA out of the box: https://docs.netbird.io/manage/networks
Connect: @braginini on Github