Problem. With media encoder

Hi guy's, 

If I send anything to media encoder with hardware encoding in the settings while another encoding was happening or another file in the queue 

The files which I sent in the queue changes it's encoder setting to software encoding. 

And I can't able to change it hardware encoding again. 

After the encoding of the previous file completed new file starts to encoding in the software encoding setting. 

I think it is a bug or something because I can able to encode the files in hardware encoding if I send them one after other and not in queue