The gcode for the Gimbal sets the heated bed temperature to zero! I didn’t notice this at first, so on my first print there was no adhesion and just a bunch of spaghettis, hair or frizz (whatever you want to call it). Is your heated bed also not heating?
To get around this, I found that setting the heated bed temp before starting the print didn’t work because when the gcode starts running it resets the temp to zero. What did initially seem work was to start the print then pause it and now manually set the heated bed to 65 or 70. Then resume the print.
But a few minutes into the print, I had the same issue experienced by Steve (the OP).
So, maybe I too have a Z offset issue However, I note that printing the calibration models or the calibration check model did not have adhesion issues.
If a Snapmaker employee is reading this, please note the heated bed bug and maybe also a Z offset bug in the built-in Gimbal example.