DIAGNOSIS The most likely culprit is the grind size. This machine needs a proper medium-coarse drip grind. If your grind is too fine, it clogs the filter and water bypasses the coffee bed.
FIX 1) Adjust your grinder to a noticeably coarser setting. 2) Ensure you're using the correct filter paper (flat-bottom #4 baskets work best for even extraction). 3) Try the 'My Brew' setting and manually increase the bloom time and pour speed to 'Fast' for more agitation.
IF THAT DIDN'T WORK Check the water temperature. Run a cycle without coffee into a cup. It should be piping hot immediately. If it's lukewarm, there could be a heating element issue requiring service.
HEADS UP Don't just add more coffee to compensate for a fine grind. That can make it bitter and still under-extracted in the center of the bed. Fix the grind first.