Beko DHX83420W Heat Pump tumble dryer terrible smell

We have the above tumble dryer, bought Jan 2020. Seemed alright to start with, but over the last 6 months it leaves the clothes smelling terrible. We have contacted Beko, who haven’t been very helpful, who have said clean the fluff filter and condenser collector after cycle and the sponge filter every 2 or three cycles. We were already surpassing this regime by additionally cleaning, washing and drying the sponge filter after every cycle by swapping with the spare supplied. All to no avail and we are now reluctant to put clothes and bedding in the tumble dryer as they will come out stinking. We have looked online and people have recommended washing the drum with a weak bleach solution followed by putting some old towels through a cycle after spraying them with white vinegar. We shouldn’t need to do this surely, especially the bleach as it might linger in the drum and mark clothes. As far as we are concerned the Beko tumble dryer has been a total waste of time buying and it looks as if we might have to replace an appliance less than 2 years old. We would give it a review of zero if asked and wouldn’t recommend it to anyone.