Td5 fuel pump noise!!!!

My fuel pump saga continues.....

My fuel pump on my td5 is noisey as hell and takes a bit encouragement to start from cold or if left for a good length of time.

Now, I have changed all the usual suspects. Fuel pressure regulator, injector seals and o-rings, fuel filter, return bleed valve on fuel line aswell as the injector harness for peace of mind. Tank breather also seems fine.

The car runs fine once running. No power loss or cut outs, no smoke except for a white puff on start up due to the pump whining on and juddery startup.

The weird thing is if I fill the tank up full it goes away and is quiet as a mouse and starts bang on each time.
Once I've used around a quarter of a tank the noise returns as does the odd difficult start. So the temporary solution is to put 20quid in every few days to keep topped up.

I'm at a loss now apart from trying a new pump I dunno what to do?
Can the pump become clogged or anything like that?

Cheers in advance

pumps can get clogged filter screens id checktheres an orange valve at bottom of swirl housing around the pump though youd expect that to only cause issues when tanks getting low, worth changing air bleed valve too

Plus 1 for filter screens, used to be a regulat occurance on mine.
First sign was always noisy pump.