I also placed my air cube at the vent and dont get single digit no matter which orientation.
Reading is not affect if I direct a fan at it unlike the samoair.
Don't know what magic they will in the cube.
But I notice air quality improve when I on my ap after 10-15 minutes and my air cube also agree.
I think if you keep the air cube static no air into it, you won't pick up spikes.
I opened my house window last Monday before the big spike and went to take nap.
Woke up whole house hazy but Aircube on registers 50+ug/m3.
I gave the air cube a good shake, it went to 120+ug/m3.
any maintemance required on the AirCube? for e.g. dust particles accumulated thru the vent holes.