VPN keeps disconnecting ubuntu 22.04, internt connection remains connected

I am using Ubuntu 22.04. Suddenly, my VPN is disconnected. My VPN stays connected for less than a minute, then it gets disconnected. I have tried most of the solutions.

solution 1: trying to run my OpenVPN file

sudo openvpn --config vpnbook-us1-tcp443.ovpn

Solution 2 : Can't connect to VPN after upgrading to Ubuntu 22.04

Solution 3: 22.04 l2tp client not working

nothing worked for me.

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