Here's a vertical shot of the pylon --
https://www.hobie.com/forums/viewtopic.php?f=20&t=41119As you can see, there's a small vent hole so that the hulls can breathe. It's possible that a puddle is forming at the top of the pylon and letting enough water in to be noticed. If that's the case, I won't worry about it. Just tip your trailer up before you start towing and let it drain.
Other possibility is some of the interior foam plug has been damaged and allowing more water than normal in. I'm not sure I'd worry about that, other than draining. In either scenario, you're not likely to have enough water enter while sailing to make a difference.
Leaks around the base of the pylon, on the other hand, can lead to problems while sailing. Water shipping along the tops of the hulls is likely to enter the hull in stronger winds, and can get to the point of being significant. Both the weight and the shifting nature of the ballast can lead to a capsize. At that point, the pylons can be under water while sitting there. Fortunately, with minimal skill, all that's involved is smearing some silicone around the base, unless the pylon is noticeably loose. In that case, you have a bigger problem as either the base has broken loose from the hull or the holes for the pylon have enlarged to a significant degree.
Jim Clark-Dawe