When you installed a new ink cartridge, but the printer still displaying it is low ink level. It is because the the printer can not detect the ink level correctly. You can try to reinstall the new ink cartridge one at a time and Install it slowly, make sure the ink level window is not empty. The printer have a sensor to detect ink level from the ink level window, if when you installing the ink cartridge and it is not horizontally, the ink level window might be empty and the printer can not detect the ink level correctly.
ink level window was empty slowly and horizontally to install the ink cartridge, the ink level window should be full