The ink level monitoring isn't based solely on visible tank levels. The printer estimates usage based on page counts and maintenance cycles.
First, confirm all ink tanks have ink. All four colors (Cyan, Magenta, Yellow, Black) must be available for printing and printer maintenance. If one is empty, printing stops.
If tanks are visibly not empty, the printer's internal counter may need resetting. Perform a 'Power Reset': Turn the printer off, unplug it from the wall for two full minutes, then plug it back in and power on.
IF THAT DIDN'T WORK: The printer may have air bubbles in the ink lines or a clog. Run a head cleaning cycle from the printer maintenance utility on your connected computer. Note: part of the ink from the included bottles is used for initial setup, and yields vary based on usage.
HEADS UP: Using non-genuine ink can cause level detection errors. Epson strongly recommends genuine ink for optimal performance. The warranty's second year requires registration and use of genuine ink bottles.