The people in charge of the AS nameservers are not adhering to certain protocols that are required for consistent domain to domain recognition and need to brush up on their recommended practices for running a web based service..., especially a forum platform involving all the automated email activity at the heart of such an operation. Or..., they're caught in a revolving door of futility switching nameservers every time there's an issue of any kind thinking it's someone else's problem, not theirs..., or both, or worse.
A recent search of globally cached DNS entries for AS still shows most ISP's across the planet don't see the AS domain either because the records have yet to propagate after a server reboot or the DNS information has changed and the new records have yet to propagate. Another DNS test shows complete failure of recognition for other entries critical in establishing proper domain name recognition. Your ISP may see AS while another doesn't. Same with routers that move the traffic from point A to point Z.
Whatever the case or other underlying problem(s), it's very sloppy server administration on multiple levels any way you want to look at it. Hopefully someone will step up and get it straightened out permanently instead of continuing to spin their wheels applying incorrect stop gap measures which eventually only make the situation worse until the system simply fails..., again.
On the other hand, you get what you pay for and some folks never learn.
No bone to pick, here. It is what it is.