I do not have an S20... and I am not a samsung expert, although I have an S10+ and the navigation experience is good with this phone.
I am however a GPS engineer and I understand the navigation side of things. You may want to check this article below first... it seems there is a known issue with this on the S20 initial release and seems to affect the Snapdragon version of the S20. This does not align with your comments about having the Exynos variant, but you might want to check the various articles from a google search.
If you want to check the satellite observations with then try to install and use a third party app such as 'GPS status' that can give you some details of the satellites that are being tracked. You only need 4 satellites to actually make a position fix, although the more the better to improve the performance. The S20 supports GPS (USA), Glonass (Russian System), Galileo (European system), and Beidou (China). It should be able to use satellites from any of these GNSS systems to contribute to your position fix.
Looking at the various articles it seems there are some teething problems with the S20 navigation experience... i am sure an update will be issued by Samsung to fix the tracking.