Since I managed to resolve it permanently... I will try to remember the exact steps (probably not possible since it was late and I ended up rebooting probably 6-7 times before it got resolved).
First, I toggled "block all incoming connections including those in the list of allowed apps" back to the default not checked state (rationale was to put things back to a state that is normal for most users).
Then I ran the network troubleshooter... which I don't think really did anything.
Then I hit "Network reset"
Then I removed all network interfaces in device manager
After doing that and rebooting - it was still causing problems. But then I killed the process - resulting in a BSOD - and on reboot - the issue was gone.
After putting my network stuff/config all back to what they were (for the most part) - the issue has not resurfaced.
Hope that helps!