DVD won't eject

A DVD won't eject from my iMac (Retina 5K, 27-inch, 2019, Mac OS Catalina 10.15.7).

The superdrive works, i.e. I can play the DVD. When I try to eject it, it makes noises but won't eject the dvd, not even partially.

I had put an identical DVD (they are duplicates, i.e. copies) in just before this DVD and was able to eject it easily from the DVD player menu.

It's a homemade DVD. Video of a granddaughter.

I've tried every way to eject it:

1) From the DVD player controls

2) Right clicking on the DVD in the sidebar

3) Select the DVD icon on the desktop and doing a Command E

4) From the Disk Utility

6) From Terminal - drutil eject

7) Pushing the eject key

8) Restarting the computer while holding down the Mouse key. This doesn't even make the superdrive make a noise, though. All the other options do.

When I quit DVD player and try methods 1 - 7, DVD player restarts and shows the DVD's menu.