Well known issue....the Localiser Sensitive and Critical Areas for the A380 are usually significantly larger than those for other aircraft.
For example, for non-A380s, the LSA at Heathrow was 137m from the runway centreline, for A380s it varied from 150-192m.
Fitting our new 32 element localiser antennas has reduced that back down to 137m, and has enabled us to develop a 'Medium' LSA for 757s and smaller that is only 82m from the centreline.