It might have fitted OK when new. Rather than Cupra saving material, these under bonnet insulation pads fitted to some makes of car have been known to suffer from the effects of heat shrinkage over time (do an internet search on ‘under bonnet insulation heat shrinkage’ or similar search).
It has been an issue with VW’s mk7 Golf. Quite a few owners on Golf forums have had their insulation pads replaced under warranty, but in many cases the replacements have also shrunk over time.