Hey,
for some reason, the struts of the IXEG are extremly "springy" in XP12.
You can easily fix that by open the .acf file in planemaker, then go to "Standard" -> "Landing Gear" -> "constants" and uncheck both "use manual gear deflections" and "use manual damping constants". All constants shown will disappear and set to values guessed by planemaker. Then, of course, save the changes to the .acf file (make a backup first!).
When you check the boxes again, the guessed values of planemaker will apear and you can play with them. Further reduce the damping constant of the nose gear to your liking.