Teacup powers off during heating

Hi all

I'm trying to test the teacup firmware on a gen 3 setup (not gen 3+)

Using pronterface I find that the whole system turns off while heating the nozzle.
Seems to be timing out rather than hitting a specific temperature.
Pre-heating the nozzle doesn't help, it still says something like "waiting to reach temperature" and never starts printing.

Anyone encountered this before?

(P.S. Please don't tell me to upgrade to RAMPS etc., this doesn't help me)

Possibly over temperature protection shutting down the hot end. See discussion below:-

Forum

Ok that's interesting. I don't think it's a problem with the hot end as I've had it working with other software/firmware.
I suppose the thermistor profile could be off or I need to enable temperature smoothing.

Thanks for the lead!