linux – Cannot read existing files from a bind mount in docker

I have a bind mount configured from a local directory to a directory in a docker container. I am able write to and read back from the mount, but when I try to read a file that already existed in the local directory I get a No such file or directory error:

root@7206541d128a:/var/lib/myapp/testdata# ls
root@7206541d128a:/var/lib/myapp/testdata# cat file_a.txt
cat: file_a.txt: No such file or directory
root@7206541d128a:/var/lib/myapp/testdata# echo hi > file_b.txt
root@7206541d128a:/var/lib/myapp/testdata# cat file_b.txt

This is the mounts information from docker inspect:

"Mounts": [
                "Type": "bind",
                "Source": "/path/to/local/dir",
                "Destination": "/var/lib/myapp/testdata",
                "Mode": "rw",
                "RW": true,
                "Propagation": "rprivate"

How can I read existing files from this mount within the container?