When trying to add two sub-assemblies to one main assembly and mating them together they don't move together as intended. I tried fixing both assemblies and made them both flexible, but they still don't work together. Can anyone help?

3DEXPERIENCE ​​​​​​​Assembly Design ​​​​​​​

 ​​ Part Design ​​​​​​​Edu ​​​​​​​