Motoman

Hi all, Acquired a brand-new 2010 F01 740i. During my demonstration drive, the windscreen washers worked properly. However, a few days later, their performance drastically deteriorated, and they now only drip pitifully at the bottom of the windscreen. There is no warning for insufficient fluid, and the headlight and NIVI washers function flawlessly. How should I begin to diagnose the problem, please? Thank you very much!