When you said you cleaned the mushroom , are you referring to the big grey mushroom shaped float at the rear quarter ?
My money would be on a gunged up level float switch . This is situated in the sump at about the 5 o’clock position. Take out the grid and filter and remove the small grey cover at the 5 o’clock position on the edge of the sump. Under the cover you will find a small grey/clear float. Remove and clean this float making sure you make a note of which way up it goes and also throughly clean the channel which the float runs up and down in . You may find thius channel clogged up with grease/fat/gunge and if it is , it restricts the floats movement giving false water levels . I find pouring some very hot water down the channel successful. Then replace float , cover and hopefullythe appliance will start filling correctly again.