Bug about custom model while touching the runway

Since Ver2.5.4.26652 my custom model cannot land normally.It always above the runway about 2 meters.the gear cannot touch the runway and I can see some sparks just under my plane.

If I change the worldID of the model to...3, for example,the problem fixed.but before this version the worldID could be anything I want.and the model could be completelly independent.

I found the worldID of offical models like F/A-18C or TF-51 can still be anything,can just be same or near to the aircraft's name.but not for custom models anymore since Ver2.5.4.26652.I mean I found some other model got the same problem.

So,if I wanna land with a custom model,I have to set the worldID to 2(mig-29)or 3(su-27)or 4(su-33)or 6(F-15) and so on,this made another bug that the original planes of these worldID just crash after I pick it in a mission if it's been set on the ground. I tested worldID=3，someones else reported the same bug to me.I strongly doubt it may happen to mig29,su33,and f15.

hope can fixed

greatings.