Personally, I've no idea what PlayX is... you'd have to look at the whole picture to determine why it's not working. I thought you were using a standard gmod hook
I didn't know you were returning false or true to a totally different script's hook system..true and false returned to it may have totally different results.
Knowing what you do now with the UCL query test of a player of a Ulib registered player, you should be able to work with whatever PlayX author and design the test for it.
As for not being able to see the results...you need to research how to see your server's console. Various hosting companies have different ways, and there is also always HLSW or software like it.