A lot of users met this problem:
When they upload an ovpn to the router, the router asked for username and password. After input these info and click Submit, nothing happens.
Here is the reason:
You have Bitdefender installed which prevent you to input password for non https website.
Make an excpetion rule and add the router’s IP (it is 192.168.8.1 if you didn’t change) in white list.