When you perform a 'Drag component' of a part (e.g. A) containing a Pattern of parts (e.g. B1, B2 etc), only the selected part and the reference instance (B1) move simultaneously.
When you release part A, the pattern follows.
Why?
Solution
This is working as designed, since Patterns often are very large, and a simultaneous calculation can be very performance intensive.
A simultaneous calculation could affect the performance negatively, making the move very slow.
Notes and References
Hardware/Software Configuration
Platform: INTL64
OS: window
OS Version: 1064
Product: SOLID_EDGE
Application: ASSEMBLY
Version: V109MP6
Function: COMPONENTS
Ref: 001-8845333