Ok, I’m after work and returned to troubleshooting. Thank you for your engagement. I did following steps:
- Uninstalled GlassWire
- Restored defaults in my firewall
- Installed GlassWire
- Rebooted to be sure
- Switched to “Ask to connect” mode
- Tested explicitely blocked several apps. Every of these couldn’t access remote sites.
- Enabled VPN connection through NordVPN app
- Suddenly my blocked apps could connect to Internet sites
So nothing changed so far, but I went further.
10. I exported my firewall rules before and after connecting to VPN - nothing was different. Only one other thing changed: public profile became active. When I don’t use VPN, only private network profile was active. But those profiles have the same settings.
11. I got another idea: uninstalled NordVPN and installed pure OpenVPN app. After importing one NordVPN profile for OpenVPN I connected to their service.
12. Aaaaaaaand… GlassWire blocks every app which has “Block” setting turned on. So with pure OpenVPN access everything works smoothly.
Well. My reasoning is that NordVPN is messing somewhere in Windows setting. I cannot track it down, because I’m not too advanced Windows user/admin. One thing was interesting, that NordVPN app has the setting to drop any connections while VPN is not active and it works. But I don’t know what is then changed and where.
Maybe you are able to investigate it further, perhaps with NordVPN folks. You know Windows internals a lot better than me for sure.
For now I will stick with OpenVPN for a while, and probably will return to testing when I got some rest
Thank you again.
Besides, I learned at least a bit about Windows Defender Firewall.