Hmm… That’s interesting!
I can see from our side that you are not sending updates anymore. The only reason why the position would still be shown like that is if the browser would be erroneously storing the last position request result - that’s beyond our influence. I have never seen it happen before, which is what makes this interesting.
Could you try clearing the cache? Perhaps Firefox has some “Private” or “Incognito” window in which you can try this?