Take a piece of tape....any color you choose (matching, accent etc.) and cover the tank level monitor indicating lights :B
They are just for show.......and are installed so that folks can obsess over them vs enjoying camping.
Could be wire connections on backside of monitor panel.
Most of our previous RVs didn't have indicators and haven't looked at current RVs for over 6 yrs.
Toilet burps....time to dump
Sink/shower start to drain slower....time to dump
Freshwater pump goes buuurrrrrrrp....should have put some water in tank