MQTT library returning error connecting to mosquitto

When you see:

1708970867: New client connected from 192.168.1.100:44538 as 29004900-0c513532-39333638 (p2, c1, k60, u'username').

Is the stuff in brackets the same for tinyMQTT and MQTT?

And did tinyMQTT actually work to send/receive data, or did it just connect?

I guess it's possible tinyMQTT/MQTT use different names for username/password/similar? So you could run wifi.dbg() (I think?) to turn on debug messages, and you could maybe see what's different about the first few messages sent/received from the MQTT server?

I just checked and I'm pretty sure that to get Connection refused, unknown return code NaN the message it received from the server had to have been cut short - it'd be receiving a CONNACK message with less than the 4 bytes it's expecting.

tinyMQTT never checks any of that so it's possible it's still receiving the unexpected data, it just doesn't care