there are other methods of installing Nextcloudā¦ Iām not a docker fan personally 
Iām a snap man myself, they call me āMr. Snapā so Iād be a fool not to recommend the snap to you.
so if you have a dedicated machine running Ubuntu, kill the AIO docker, remove the image (make sure its shut down) then follow the installation instructions: How to install Nextcloud snap and donāt forget to read the docs first and check out the wiki, thereās plenty information in there!
youāll bump into this sooner or later if you want to share your NAS in the snap;
and see this if youāre sharing NAS over samba
so now youāve got plenty to study and know where to find stuff to help yourselfā¦ Nextcloud is the way to go, thereās no doubt about that.