ISP issues can be frustrating. One tool to get a look at the upstream path is WinMTR.
This tool is free and can be installed on multiple OS's.
Open Web browser and Download WinMTR ( WinMTR )
Open WinMTR, enter a host IP address and press start. For example, use mdsmanager.com , yahoo.com , etc, or the website(s) having issues.
Note: Google’s DNS is not a reliable target since they are employing ICMP filtering in some regions
This tool will provide statistics of each hop along the path with packet loss seen.
Cisco has a good explanation here
Another how to https://us.battle.net/support/en/article/27780