Open VPN with 2FA

I just enable Google Authenticator and started the server. Then Import my profile to OpenVPN client in Android device. When i start connect asking username and password (ticked to save password). I added user name and password (pin+Google OTP). Then Connection is success. Then i manually disconnected the client, and Reconnect again. At the time i got prmpt asking for Pin (Multi-Factor authentication). I entered Google Authenticator OTP and i got the message auth failed. So is it a limitation? or what kind of OTP i need to type in ?

This is currently a known issue when both a pin and Google Authenticator are used. Verify that password saving is disabled then enter the pin or Google Authenticator code when prompted. The two values should not be combined if there is a prompt for one.