Leaks air?

Hey, cool product in theory - but I've tried installing the sensors on 2 very different bikes/tire setups and in both cases the tires will leak to flat within a day or so. Bikes: Ducati Multistrada 1200S - tubeless, cast wheel, 17"/17" Husqvarna 701 Enduro - tube type, spoked rim, 17"/19" The installation is pretty straightforward so I'm not sure what I could have messed up. Naturally, the tires don't leak air when I use the standard valve stem caps. Any suggestions?