Really? I'm very surprised by that. Maybe it's a British thing, but ours works fine, my Dad has a different one and that does too...
This is (almost) the one we have, it actually has two plugs / separate-side heating. The one we have actually has a display to show what heat setting you're on, so not sure if this the exact same but...
https://smile.amazon.co.uk/gp/product/B002QS61NO/ref=oh_aui_search_asin_title?ie=UTF8&psc=1