Yes, it's possible that Apple's servers are also getting overloaded. I'm suspecting it's a combination of some issue on Apple's side plus some issues with TM. Maxis broadband users seem to be unaffected. Maybe the relay between Apple's servers/mirrors and TM's servers is wonky somewhere?

Was the same for my place as well. Full speeds on everything except App Store downloads and updates. Thing is, if it was an issue with Apple alone, then all ISPs in Malaysia would be affected. This problem only seems to affect Unifi users (and maybe Celcom, still cannot confirm), so that's why I suspect the issue is at a very specific point in the chain - Imagine a big longkang splitting into a few smaller longkangs. Apple is the big longkang, while the Malaysian ISPs (UniFi, Streamyx, Maxis, Digi, etc) are the smaller longkangs. The part where the water from Apple's big longkang goes into Unifi's smaller longkang seems to be sumbat right now. Cannot say whose fault it is yet. None of the Apple related sites or Apple's own status page have posted outage reports yets. Only clue I can find is here; https://downdetector.com/status/itunes (click the map) but those are individual users making the reports, so we can't get a rough estimate of how big the problem is.