"Interestingly, Tyreleader’s website currently doesn’t have a ‘wheels’ section, so they’ve either stopped selling alloys, or they may have decided to stop taking any more customer orders for wheels until the outcome of the Brexit negotiations are known."
Well, just done a little bit of searching and the French equivalent website for Tyreleaders (which has the same configurator etc as Tyreleaders.co.uk) will sell you some wheels if you live in France.
https://www.centralepneus.fr/So I guess they have given up on the UK either because of the current port disruption, Brexit or both. Perhaps they have UK stocks of tyres which I imagine sell in greater numbers than wheels.