I tried about 20 zaps between my Minibits and Alby, half of them received a {"result_type":"pay_invoice","error":{"code":"INTERNAL","message":"Lightning payment failed."}} Back from Minibits NWC relay. 

At some point, the relay was rejecting any zap from my phone, but accepting all zaps from the emulator. 

All these tests with Tor disabled. 

When succeeded, the payment took about 12 seconds from submission to the NWC relay to the response from the relay.