Markoz wrote on Apr 29^th, 2020 at 1:28am:

On all my flights where I've had to level off below 10,000' (after the descent), I have never had a problem with the 767 holding the speed around the 240-250 knots.

I think the question was when you're in cruise mode below 10k does the plane command 250 to adhere to the requirement or will it want to do over that.  Like you, I've never seen the plane command above 250 below 10 in the descent mode (or climb for that matter).

I did a flight from ONT to LAX and I never even looked to see what VNAV ECON Cruise had in store for us.  Once off the ground we were held low with crossing traffic so I used V/S to avoid any TCAS issues so we never even entered VNAV cruise. 

I DO know on my previous plane the FMC wouldn't adhere to the 250 below 10 in cruise unless we intervened. 

As for this being a bug or not, standby and I'll have an answer soon!