According to this poster who knows a lot more than I do, the switches (LZW30/LZW30-SN) may indeed leak a bit when off. I noticed this on a fluorescent fixture that flickered a tiny bit every few seconds when the switch was off. Perhaps the dimmers are the same?
You may indeed need a bypass however before giving in you should check parameters 21 and 22 are set according to your installation.
Parameter 21 should be 1
I’ve read the parameters 21 and 22 may not “take” when set by the buttons on the dimmer. Try from your controller (if you haven’t already) and if your controller can read the parameters, all the better to verify.