Struggling to find a Roku device in stock to buy in the UK? You’re not alone. Roku devices are sold out nationwide, leaving frustrated fans considering rival set-top boxes, including Amazon’s popular Fire TV Stick range. Roku-powered Smart TVs remain widely available in the UK, but there’s currently a shortage of the company’s streaming dongles, including the Roku Streaming Stick 4K, Roku Express, and Roku Express 4K. Trying to find one of these USB-sized devices ― which plug directly into the HDMI port on the back of your telly and unlock access to the Roku software and a slew of popular stre…