Hello, thank you for your submission!
I can confirm that the Fountain of Refreshment is intentionally and exclusively a light source, as @Arsenalcontrol mentioned.
The problem you’re facing with markers for revisited or new areas not working does seem like an issue, could you please share a video of that behavior in action? Does it also occur if you join a different server or start a new single player game?
We’ll pass this one to the developers for further investigation and will be sure to forward any further information that you can provide as well!