So.. I've resolved the issue and thought I'd follow up (even though it's a little embarrassing!)
Basically, when programming, somehow or other I managed to program our proximity tags as "Duress Codes". So the System was appearing to unset without issue when in fact it was being logged as a duress code being used which is what was causing the "silent" alarm I was experiencing.
Absolutely no idea how I managed to make such an obvious error but thanks for all your help, it definitely pointed me in the right direction
Basically, when programming, somehow or other I managed to program our proximity tags as "Duress Codes". So the System was appearing to unset without issue when in fact it was being logged as a duress code being used which is what was causing the "silent" alarm I was experiencing.
Absolutely no idea how I managed to make such an obvious error but thanks for all your help, it definitely pointed me in the right direction