Same issue for me as others. I too went through the manual bootloader procedure. My problem is that Roasttime 2.05, 2.06 and 2.07 all will not now let me download and try 448 or 444.
It will only procedure if I choose 449 debug. So that is what I have loaded, and the device doesn’t now actually do anything useful. The fan is on high all the time, the readouts work and it boots fine. It will say pre-heating and such, but nothing happens.
How I can force the latest stable release firmware?
Also 2.07 shows a long build release number instead of 449 for what is currently on the device.