That's what they told me and I have no reason to doubt it.
I verbally informed them going in that the unit had to go through a normal cycle. (No manual turning it off and on, leaving the temperature control on the thermostat alone.)
Once it had gone through its routine of normal... then sometimes working on the 2nd or 3rd try... then failing to lite at all... it would "rest" for approx. 12-20 min., then do this over again. It did this from the time it was first installed.
I should have had it all in writing and taped it to the unit when I left it at the Service Center. I'm sure they didn't understand the above due to the fact that after they kept it overnight I got an email stating that the unit fired up, first try, from sitting all night. It always did fire up normally after a "rest."