Recently installed only shows 5 latest updates (3tb external) be nice to get a list to see...

Check Settings>System>Storage and see what drive defaults as the installation location.

Hi. Both the internal (which only has one game installed) and the external which has 24 games installed still show available space. 727.6GB on internal and 3TB on external. Internal is listed as the capture location.

I dont see this as being a format issue, as Xbox 360 would of taken care of the correct format when you first connected it.

I would try to manually update your Xbox using a usb drive, just to make sure 100% that you have the latest and greatest update (even if it shows you do, something may of become corrupt or not installed properly).

Not all external hard drives work/work well with Xbox (The WD My Passport) shouldnt have an issue though as that is what I use (Just the 3TB version)

If you cant get around the problem by doing a re-format with your Xbox, or some other magical solution, id recommend exchanging the External Hard drive. If i remember correctly, WD backs up their drives with a 3 year warranty.

Really? Your doing well. Mines already full and I've got myself a nice 3tb external that should keep me going for a while!

Check this support, Console doesn't detect external storage especially the step

Solution 1: Make sure you’ve installed any recent updates to Xbox One

It’s possible that there were recent updates to Xbox One and that you need to manually update your system for it to detect your external storage. To update:

1. Press the Xbox button
    to open the guide, and then select Profile & system >
   Settings > System > Updates & downloads.
   
2. If you see Update available, there’s an update you need to install.
3. After you’re done installing the update, go back to
   Settings and select System > Storage. See if your device appears in the list.

I filled up the 500 cb on the Xbox , but just recently added an external hard drive. Now I have 3tb of space.