Maybe you have your GPS turned off?
I was in a glasshouse and had GPS locate me about 2km away. I think the two different angled glass roof planes might have caused it. I know of people that have had issues on remote beaches, but not sure if that was reflection from waves or just map overlay inaccuracies.
Has it happened since? If it was just a one time thing not sure it’ll be diagnosable.
Hasn’t happened since
(Please open a new report if it happens again)