Well count me as one of the many people still having GPS issues with their iPhone 8 Plus. I got my phone about 2 months ago and the GPS has been unusable since day 1. Multiple issues. Often when at a complete standstill my position will float around the screen. What is most common though is the constant freezing of my position on the screen while driving. This occurs whether I am using the built in Maps, Google Maps or Waze.
I still have my old iPhone 6 Plus that I gave to my daughter when I upgraded to the 8, so I did a test. I entered the same destination into both the 6 and the 8 and started driving. My position on the 8's screen would randomly freeze throughout the drive, sometimes for more than a mile at a time. Then my position on the screen would suddenly jump and catch up to my real location and work fine for a few seconds before freezing again. This process repeated itself throughout a ten mile drive. Meanwhile, the 6 that was sitting right next to it never froze once during the entire drive. Both are running iOS 11.2 and both are on the Verizon network.
After several weeks of trying multiple iOS updates, settings resets, and complete factory resets of my 8 Plus with no success, I finally went back to the Apple store today and was given a brand new iPhone 8 Plus. Sadly, the new 8 Plus is exhibiting the exact same problems. The phone was even set up as new phone without restoring a backup. This is beyond frustrating.