This was done to add the external web process NaCl token request validation in Pritunl v1.32.4512.98. This adds an additional NaCl based cookie that allows the external pritunl-web process to validate a request before forwarding it to the root pritunl process where it then passes the standard session validation. Although this feature is less isolated when an API key is configured as the API keys can only be validate in the root process. This mode is indicated by web_auth_strict=false in the startup log message, it will still use the validation but the request will reach the root process where it will enforce the NaCl token check only for non-API key requests.
The problem was the other /key handlers are open for the client connection authentication and that one handler was an admin session so it needed to be seperated from the other /key handlers. This is visible in the pritunl-web/handlers/handlers.go. This has been the only breaking change to the API it’s unlikely other changes will be made.