I've had one other person say they can't zap me, but I didn't go into config details with them.

I've been running with Albyhub and my own domain for a while and only had two reported issues and I send / receive zaps a lot.

If you read my article I published on habla.news the json file that sits on my website, that effectively forwards the payment to mhardcastle@getalby.com is a little different to most json files (like Wallet of Satoshi), so maybe Alby have introduced some non backward compatible functions within their config. 

Thanks for letting me know about this and thanks for the zap.