What 8.8.8.8 is good for is detecting if it is a:
computer to router to isp to internet issue, or just a game issue.
Google is very reliable, so it's a good test.
Check the gateway address of ipconfig and that is your router address.
Then start 2 pings (2 command prompts):
One ping to google.
One ping to your router.
When you rubberband next time, if google shows the delay, and your router does not, it is not your connection to router, it is ISP, you can call and have them and then try to troubleshoot their modem/network.
If the delay shows on both, then it is your computer to the router.
If you are on wifi, what you will want to do is check what channels are high usage around you and change your router to a new channel.
I have a soundbar that is 2.4, and forcing that to stay on one channel and moving wifi off of it was good.
Check out articles like: https://support.metageek.com/hc/en-us/articles/200628894-WiFi-and-non-WiFi-Interference-Examples
This will show you how even someone starting a microwave, or worse, a DRONE can make your wifi congested, and thus rubberband.
If you are wired with ethernet to your router, try another cable (sometimes kinks can really mess with CRC errors that most routers don't show), I would upgrade firmware on it, or if it is really old, replace it.
Good luck!