Yeah I considered that as well which is why I tried editing/writing/moving files from the docker console, so inside the TMM instance. It all works fine in there so the docker instance itself is not the issue, it has to be something with TMM it would seem.
I also ran the docker safe permissions script from the unraid tools menu as well to make sure permissions were not an issue.
The strange part is it used to work fine, it just stopped working for some reason.