assuming here that your global contact is bonded.
if so, it means most likely your problem is unrestrained. when bonded, the assembly is held together. without it, your problem is unstable. use soft springs to confirm this.
if you're able to add a bit of stability to the problem and your parts are deforming a lot, you can try the large deflection option for static. if that works or potentially doesn't work. you may need nonlinear.
Just sent the File over for your review.