How to use Virtual sequence containing different sequences running on different sequencers?

Some how I think you missed the handle for the sequencer:

Set the Sequencer:

uvm_config_db #(your_sequencer_name)::set(null, *, “your_sequencer_name”, your_agent.your_sequencer)

Get the sequencer in the Sequence using it::

if(!uvm_config_db #(your_sequencer_name)::get(null, get_full_name(), “your_sequencer_name”, SEQUENCER_MY_h)) begin
`uvm_error(get_full_name(), “CONFIG_DB_ERROR : YOUR SEQUENCER NOT FOUND not found”)
end

You need to get the sequencer handle , Hope this will help !!

P.S: There are many different ways to do the above the task, the above one is the one I am using.