miele washing machine novatronic w980 ?

hi any clues on a 30 wash gets to to rinse and alarm sounds , i then tip it forward to empty the sump i then have put it on spin, after spin and water comes drains out as normal but the alarm comes on again, i then turn it off, take the clothes out and tip it forward again to drain the sump.help how is water getting in the sump. no visible leaks.