I use a trusted Makita Impact with Spax Screws (square drive) from Menards. I only use wood and never composites but going back to wood class in college, I think the Trex is plastic mixed with wood, maybe other products now and they're giving you issues, I can easily see the plastic melting and putting too much torque on the drill.
With a few exceptions, I always predrill a hole, it doesn't have to be full size, even smaller diameters help out a ton. I work around a lot of decks, if you have one 20 years old, your doing great, at least up here where we have four hard-core extreme seasons.