Getting NextcloudPi working after a reboot

I’m installing NextcloudPi in a Docker container.
The problem I’m facing is that even though I specify that the container should “restart always”, the server is not accessible anymore after I reboot my RPi 4. The command I ran to install the container:

docker run -d -p 4443:4443 -p 443:443 -p 80:80 -v /mnt/usb/ncdata:/data --restart always --name nextcloudpi ownyourbits/nextcloudpi [IP]

I can confirm that the container is running after a reboot, and the data folder is automounted.
When I visit the local server (the RPi IP) I get “Problem loading the page” error. I have also confirmed that the IP is still whitelisted in the ncp-config - trusted-domains file.

sudo docker exec -it nextcloudpi ncp-config
config → nc-trusted-domains → IP

Am I missing something or is rebooting and keeping the same NextcloudPi container simply not possible?

Thanks in advance and sorry for my english (I’m not a native english speaker)

I use --restart unless-stopped flag, but this shouldn’t be the issue. I don’t have troubles after rebooting, unlike you, i have the data folder on SD card. I suggest you to create similar new container, at least you will know if the problem is somewhere with “external” usb storage:

sudo docker run -d -p 4443:4443 -p 443:443 -p 80:80 -v /ncdata-test:/data --name nextcloudpi-test ownyourbits/nextcloudpi YOUR_IP
sudo docker update --restart=unless-stopped nextcloudpi-test