my test stuck in uvm sequence `uvm_send()

when I run a test case by UVM

I found that the case stuck in `uvm_send()  it can not print the log behind uvm_send

maybe the connection is wrong or disconnect between sequencer and driver , so that the driver's " seq_item_port.try_next_item(req) " will always get NULL

right?

so how can I fix this problem?

Thanks a lot!!!