The last two items may be your issue.
Public WiFi networks can be filtered and some services disabled.
May be worth disable webroot for a test and if that is the issue then add the create folders and create itself to the exclusions in webroot.
Add the Arduino directories to your antivirus / anti malware / other security exclusions.
So that would be at least two of the following for the desktop IDE
C:\Program Files (x86)\Arduino
C:\Users\yourname\AppData\Local\Arduino15 depends on IDE
C:\Users\yourname\AppData\Roaming\Arduino15 depends on IDE
If you have your sketches set up in a different location it’s also worth adding that directory to the exclusions also.
Additionally if you also use the online IDE “CREATE” the following directories.
If you have installed to a different drive swap the drive letter as needed.
If you also have an unzipped IDE installed that path should also be added to exclusions.