Content won't copy between external hard drives or even back to internal

You are using transfer, which is to move the contents of your internal hard drive to the external hard drive instead of copying, you do not need to manually delete the contents of the internal hard drive (because they are already on the external hard drive).

You can easily copy games between internal and external storage like a hard or flash drive.

I think what onyx was saying was, instead of doing what you did, copying them all to the internal of the new console, a much better solution is to get an external hard drive (somewhere in the 2+ TB range) and LEAVE all of your content on that drive. You
can then plug the External Drive into ANY Xbox One and not have to reinstall or re-copy any of your content, it'll just be there and work.

You can also have your console set to automatically install any new items directly to the External Drive instead of the internal, so you can get a new console, take your hard drive to your friends, etc. and never have to re-transfer all of that data.

hi - you can move all of your internal games contents and apps onto an external drive (subject to space). there will still be some contents on your internal such as the operating system. if power is interrupted or the drive is disconnected you will just
need to plug it back in and it will work OK. Transfers dont take long between drives as usb3 is quite fast.

I moved my games from the internal hard drive to the external hard drive to see if my games won't kick me to the dashboard I tried it yesterday with a external hard drive I had never used for my Xbox. My games were never on the external hard drive they
were in the internal hard drive. Also I downloaded trove and it kicks me to the dashboard as well.