Regardless of manufacturer obligations: if the product is not as described then you have a claim opportunity against the retailer. Any claim does not necessarily require a return.
Check the product description at the time of purchase, and if that description makes a statement that you can now show to be inaccurate then you have a claim route against the trader that advertised and supplied the non-conforming product.
Not quite comparable but indicative of how other security product manufacturers approach product non-conformance / performance issues: Swann is voluntarily offering full purchase cost refunds or 40% discount against new Swann products for buyers of its Intcam outdoor cam that has reached end of life due to a possible battery issue (no security issue):