Discovery plus keep going back to start of show!

blackstar

When watching a show on discovery plus and I exit the show and watch something else either on sky or a other show on discovery plus and then I return to the show I was watching on discovery plus it either returns to either the start of the show or much earlier on in the show. Meaning I have to fast forward to find where I left off. And having to wait through loads of adverts which I have already been through. I have contacted sky and they said its not an issue from their end. Anyone any advice please

 Thanks.