Vw polo electric Windows failed

[Adamsplatt]

I have spent several months on and off trying to get the Windows moving up and down continuously. After changing the window Ecu the Windows so etimes start working normally, maybe for a few minutes or even a few hours. Then they pack up again. I have checked all the wires in the loom. I have cleaned and lubricated all connectors to door pillar and all items in door. Have changed the door module. Have swapped the CCM for another unit. What ether I do the fault recurs. The passenger window operates from its switch if I prime it with the passenger door lock, but then stops working too after driving a bit. When it works everything is normal. But only for a short time. I have tried the battery disconnection tricks to reset the CCM and Ecu, but makes no difference. I even have a second CCM, which makes no difference. Same intermittent working. Seems should be a connection problem, or perhaps the CCMs, both of them? Are misbehaving. Is there some reset trick I am missing? The vag readout provides no faults codes. Next idea is to try a replacement loom, but I have checked the existing one again and again. Each time I get it to work is by disconnecting and reconnecting the windo motor and its Ecu, but then it fails again....Very frustrating! Any suggestions, solutions?