networking - Windows 10 Private Firewall Blocks All Internet Traffic

I experience an interesting issue lately.

Sometimes when I turn on my desktop PC (Windows 10 Pro 64 bit v1803) I have no internet connection. After some searching I realized Windows' Private Firewall is on. If I turn it off, I can connect normally. Sometimes, when I reboot my computer the firewall is turned on again by itself and I have to turn it off to connect to the internet.

1. Is the private firewall supposed to be on or off by default?


2. Is this behavior suspicious?


3. Why is this happening?


4. How can I solve it permanently?