ASDA coughing ban – at odds with latest government Covid-19 guidelines?

ASDA are telling their customers ‘not’ to enter their stores if they have a continuous cough.  

https://www.asda.com/feeding-the-nation

However, the latest government guidelines advise that: 

‘You do not need to self-isolate if you just have a cough after seven days. A cough can last for several weeks after the infection has gone.’

https://www.nhs.uk/conditions/coronavirus-covid-19/self-isolation-advice/

This effectively means that a potential customer who has recovered from the illness but still has a cough is now potentially being penalised by the store and barred from obtaining essential goods.

Do ASDA know more about Covid – 19 / coughing than the government does.