Hi,
I’m a noob manjaro and linux user.
I have a raspberry pie where pihole is installed on it.
Pi-hole is very useful for me to also monitor the query’s of my devices connected to my network. I used a lot to block ads and tracking on my custom black list’s.
I found that manjaro is connecting regularly to ping.manjaro.org.
Is there a special reason for this?
Can i block this connection without consequences?
Thank you forward for the answers!
It is checking…
Without consequences? Not really. 
Define consequenses 
but if by consequences you mean not breaking your system then yes. You will lack some functionality - but you will not break anything provided you do it the right way.
From my notepad
NetworkManager is a system service controlling your network connection and it checks if an internet connection exist - this defaults to 300s.
Copy the existing configuration to /etc
sudo cp /usr/lib/NetworkManager/conf.d/20-connectivity.conf /etc/NetworkManager/conf.d
The append the following value to the file interval=0 - use a text editor or the following command
echo "interval=0" | sudo tee -a /etc/NetworkManager/conf.d/20-connectivity.conf
Restart the service
sudo systemctl restart NetworkManager
The disables the check.
You can change the uri to what ever service you trust or can control.
But you should consider the implications as you are removing the possibility of NetworkManager knowing the state of your internet connection.
The host ping.manjaro.org is not used to check for updates - this is done by pamac using your configured mirrorlist. This can also be disabled in pamac settings.
There is also this topic on Archlinux BBS
So if we’re fine with defaults but the check had to be disabled temporarily – for example, as a workaround for temporary connection problems – then is it advisable to remove /etc/NetworkManager/conf.d/20-connectivity.conf as long as successful checks are back to normal?
There is no need to remove the file in /etc - in fact if you want change the defaults then the file in etc is the place change values.
You don’t need to revert your settings in etc - as the system vill work with other hosts as well.
Maintaing a change-log for the changes is highly recommended - such a logbook is very good resource when troubleshooting - your system.