A FTE is almost always mechanical, especially if it's trying to load the next round.
Check for out-of-spec ammo or other cartridge problems. Since it's intermittent and you're shooting a new ammo brand/type this would be my first guess. Also look real closely at the extractor; I don't think it's not in position (if it fails to eject every time that generally means the extractor's not seated properly), but the hook may be worn such that if a cartridge ends up well-seated in the chamber after firing the hook may slip off. The cartridge rim may pose the same problem. Put em together and ammo that doesn't have problems in any other gun, fired from a gun that has no problems with any other ammo, will start failing.
I haven't had any ammo-related failures in my P95 (my only failure to date is a failure to lock back and that was my fault for resting my off thumb on the slide lock). I use Federal 124gr defense loads and either WWB or Remington UMC plinking ammo, and the gun's run great with all of it.