try to identify if other Maxis Fibre users are experiencing the same problem or not. if there are a few, then you should contact Maxis and describe to them the issue. but before that, you must first identify certain aspects; does it only affect updating only? have you tried downloading an app and see how fast it downloads? what about surfing online or watching YouTube? is it slow as well? and what about the iOS firmware? does it download fast or slow? have you tried resetting your router (off for 10-30 seconds and turn it back on)? have you tried logging out and back in your Apple ID in the App Store settings in 'Settings'?