I have seen a similar problem with a Centronics cable on some early IBM clones (gives the age away

) where the PC would not boot until the cable was connected to a printer or removed.
Thought that unterminated cables was a problem from the past !!
Goes to show that old problems are being recreated by yet another generation that fails to learn from what has passed before

Every generation thinks that they know it all and the last generation were idiots

Very surprised that it was an apple cable, I thought they were engineered to always work, virtually even through a EM Pulse <jk> (At least they charge you as though they would

)