Use --contain and --bind in singularity run command

Question

I was experiencing a bunch of trouble with python packages for a Docker container running on singularity. I managed to solve the issue by adding the --contain flag to the singularity run command. But now the --bind flag doesn't seem to be working (i.e. there is nothing in the /mnt directory). I read that --bind can't be used with the --containall flag and so I figured the --contain flag should be fine. Any idea why this is incorrect or how to fix it? Thanks!