Indesit Dfg15b1 beeping during fill

I have a Dfg15b1 dishwasher that’s 2 years old and it’s started beeping when it’s filling with water. The first wash led flashes but once the fill has finished the beeping stops and the led also stops flashing. This then repeats when the machine tries to fill back with water. The machine then only seems to do a pre wash no matter which program you select. I’ve taken the side panel off and I can see water going through the flow sensor from the inlet valve and spinning the fins. It does seem related to the fill cycle. Maybe a warning that there’s not enough water coming through but it does look ok?

I was thinking maybe the inlet valve isn’t opening enough or maybe the flow sensor is faulty. Or am I completely on the wrong track?

Any ideas?