I think it might be because of full (or not) reservoir.
Yes probably the case - needs emptying and cleaning and resetting reset tool here
Be extremely careful so as to not damage any of the data cables.
Remove the control panel then the scanner assembly.
Disconnect all cables from the circuit board
(you may have to remove the board), and unscrew and lift off the upper housing. They are all held by visible screws and tabs.
Then remove the sheet feed assembly (don't forget the screw on the underside and on the left by the gear assembly.
Remove all screws holding the printer to the lower case (two screws are hidden under the scanner hinges).
Next disconnect the drain tube coming off the pump. Finally remove the printer mechanism.
The waste ink pads are now clearly visible.
Its easier just to reroute the waste ink tube to a waste bottle and reset the counter like this