You kind of answered your own question. You had flown from that location before and had to go thru the process to "unlock" the location; but this one time it did not ask you to do so. That alone should have set off bells in your mind that something was amiss - thus finding out satellite issues kind of after the fact.
Properly setting up your drone before flying is a critical issue - almost every newbie video I've seen on YouTube / others covers this very important aspect pretty well. Having the drone set to land when an issue happens is not wise to me. You found that out too. Setting it to hover or RTH should be the go to setting, not land - esp if you fly a lot over water or other places where landing would end up losing the drone.
Highly encourage you to watch quite a few videos on how to fly your drone of choice - as each drone from the Mini to the Mavic Pro are way different in many respects. I've watched quite a few on my
Air2 and still know about half of its features. So, until I learn more of them - I fly very conservatively as losing a $1k drone is not my idea of a good / fun time.
If Norway has "drone insurance," I'd recommend it as a failsafe, as DJI is real finicky on responsibility and replacement of the drone - even with Refresh and all their additional replacement items that earn them A LOT of money in the long run - as if they can blame it on pilot error - guess who pays - NOT DJI.