Getting similar behavior on my unlocked s20 in Eastern Canada. First couple weeks were fine, but last few days it can take a few minutes to get a good lock, if even then. Thought it was because I was in car, but it also had issues in my coat pocket and using strava, cycling outside for 40 minutes. Jumped all over the place.
I thought it was just me, glad to see I'm not the only one. Hopefully they fix this asap with a software update. Waze and Google maps or any app using the GPS have an almost impossible time getting a GPS lock until I move or start driving for sometimes several minutes. Did not have this problem with my Galaxy S10e so it appears to be an issue with the Galaxy S20s at the moment.