How can I detect if two magnets are coupled?

[GeriX]

Hello everyone!
I´m trying to build a sensor, that are mounted close to an array of neodymium square magnets. It is supposed to detect the polarity of the closest magnet (wich works fine with my Hall Sensor 49E) and whether there is another second magnet coupled to it (behind it).
As of my understanding, the detectable field should extend in axial direction, when two magnets are coupled together. However I am unable to observe a change in the detected values, whether I only apply one or two magnets.
Can you suggest another sensor or signal processing strategy, or is just my physics understanding wrong?
See the attached fotos for understanding of the configuration.
Thank you!

[MasterT]

Board you have, likely build with comparator - trim pot to adjust threshould. Post circuits or link to data sheet, in short you need linear amplifier or if magnets close enough DMM 'd be sufficient

[GeriX]

Ok, I desoldered the Sensor from the PCB and can now detect a very slight difference when coupled, so this and a linear amp is a good solution, thanks!
PS: What is a DMM?

[MasterT]

Digital Multimeter (DMM).