Sorry everyone, I'm not sure exactly what's happening, other than it looks like the pool is getting banned by the XMR pool. I don't have time right now to do in-depth troubleshooting, and the last time I tried emailing them, I never got a response. The only guess I have is that a (possibly malicious or unintentional) miner is doing something to cause this ban from SupportXMR (on both Foundation and Hanalani pool), because our (Hanalani's) miners have moved to an internal private pool, and it's working fine.