Miele G1143sc has a problem filling

My G1143sc has a problem filling. The problem is intermittent and I’ve had two independent engineers trying to fix it. I’ll ask the second one to come back but it would help to have an idea what the problem is.

At its worst, after 1 minute from start up, the red Infill / Drain light flashes six time then the light is solid red and it’s accompanied by a disconcerting banging. The machine does this several times and either proceeds to start the wash cycle or stops completely. If the machine continues it may work until the cycle reaches about 75{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} completion then – presumably when the rinse / final rinse cycle starts – the problem may recur.

Over the last two days, I’ve tested a procedure. That is, I’ve used a turkey baster to remove water which has stayed in the central (drain?) hole presumably overnight, follow the previous days’ wash cycle. That “drain hole” is visible after removing the mesh panel under the lowest water-dispensing-swing arm. I assume it’s the drain area. I’ve cleaned all the parts. Then, with no residual water in that hole, the machine works flawlessly from start to finish.

I’ve tried to add a 186kb sized photograph here but failed, despite – as I understood it – a maximum 2mb add file limit. I get a dialog box / error message saying “upload failed due to your usergroup’s upload quota. This [photo you are trying to add] will require 201.8kb but you only have 19.5kb of 19.5kb remaining“.

Any ideas on what the problem is with my G1143sc would be much appreciated.