I agree with Steve, one of the bags has probably gone.
best to get it sorted asap as the pump will keep trying to push air into that side and it’s simply not designed or able to run for long periods, it will fail in fairly short order (been there, done that!😔), it takes the 40A Relay with it too.
‘oem’ parts are made by non Audi specialist manufacturers/suppliers, eg, air pump is same as used by Mercedes, RR, Range Rover, Bentley, etc. so I bought a pump from the US manufacturer for £300 instead of £1300 from Audi.
single Audi airbags arent too bad, but if it’s more than one, I’d look for the US made upgraded versions that used to come with a lifetime gaurantee and replace all 4.
depends how long you plan to keep it tbh.