Beko WMA1715 - RUINING THE WASHING?

The clothes are randomly coming out of the machine feeling sticky and hard (My granddaughters baby blanket is on the line looking like it is made of concrete!). It doesn't seem to matter what program they are on (long, short hot or cold) and it is not consistent. However once they have 'suffered' from this I can never get them back to normal. It is almost as though none of the product has been rinsed out - it doesn't happen to every load and I have sat and watched the machine taking in water and emptying. About 3 years ago a similar thing happened so I brought this machine - Could it be a plumbing problem?