AMS simulator lost some blocks during simulation

I tried to run AMS simulation with one block using verilogA code. When
I generated netlist, this block is in the netlist, but after
simulation, I couldn't find this block in my simulation result. Does
anyone have any idea about this problem?

My description may be too simple. Since I am pretty new to this group
and AMS simulator, please let me know if you need further information
to answer this question.

Thanks a lot.
.