The Explore feature, which normally blacks out the parts of the map that are unexplored, is entirely uncovered upon entry. Nothing else appears to be different. I tried to replicate this issue four times, each prodiucing the exact same problem, and using different pets (Hecuba, Garmr, Emerald, and Arrow) - none of the pets have any gene to increase their view of the map; this all happened around .12:30 noon to 1:00 PM (22:30 - 23:00 game time) on 8/29/2018. I use Google Chrome, but I don't know the OS version I'm using.

You have the Travelling Magician in your inn.

He reveals the whole map to you. This is a feature, not a bug :)

Oh! I was completely unaware of that feature. My apologies.

Yeah it took me by surprise when I first started playing too :)