Blood glucose test

Hi everyone hope your all ok. I’m a bit confused, I tested my blood glucose tonight using my last strip on aero glucomen which was 7.1, then checked it on my nexus glucorx as I had a new pack of strips and it was 4.5, both tests was done straight after each other.

I expected them to both be the same and don’t know which one to use now and which result is correct.

Jason