Sounds representative, it didn't even try to stop you!

Everyone else is saying secure boot should be correct. I was unable to load my nvidia driver until disabling secure boot, but I luckily had integrated graphics. What I think happened is you switched to to nvidia drivers that required proper secure boot before it would load. The drivers that are loaded before that don't require secure boot to be setup so that's why you had an output.

This is just an nvidia thing unfortunately.