Mixing sounds using ffmpeg with offsets, itsoffset not working

I am trying to mix three sounds using ffmpeg on android. But I want the last two sounds to blend with the first sound at some offset. I am using this command:

ffmpeg -i input1 -itsoffset 5 -i input2 -itsoffset 10 -i input3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 -strict -2 output

      

        
        
        
      

    

I gave an offset value of 2 in 5 seconds and an input offset value of 3 for 10 seconds. But it just mixes the sounds at the beginning of the input1. In short, itsoffset doesn't work. Any ideas?