Sainsbury's chipotle paste has some of the lowest reviews (with only a two star rating) on Trolley.co.uk, which pulls in reviews from different supermarkets' own websites. See here for possible alternatives:
https://www.trolley.co.uk/search/?q=Chipotle+Paste&suggested=1
(Click through to see which supermarkets sell each product).
In particular, I note that the Gran Luchito product is well-reviewed on many websites. For example, a reviewer on Ocado wrote this: "Delicious product.
Thick and rich texture - not watery like other brands. Wonderful, deep chilli heat and flavour but not too hot. Leaves your mouth and tongue tingling afterwards. Would definitely recommend".
It's sold in Sainsbury's (as well as by Ocado and in Waitrose and Tesco), so you should have no trouble in getting hold of it:
https://www.sainsburys.co.uk/gol-ui/product/cooking-sauces-all/gran-luchito-chipotle-chilli-paste-100g