Fedora will not boot

Setup:

Hardware: Dell Precision 3670 Tower 

Bios: 2.12.0

My Dell workstation has been running Fedora Linux for more than a year. A couple of days ago it started misbehaving, and I concluded that the SSD was toast.

I got a new one (this time a NVME, and put it in. Booting from my Fedora 39 Live usb stick I installed fedora on the new SSD. Rebooting and going into the bios, switching to UEFI, the bios say  I have Fedora as the single choice.

However, when I then boot I get an error that there is nothing to boot from.

After trying this a number of times I put in a standard hard drive and installed Fedora on that. I was the able to boot from that.

I decided that I could live with booting that way for a while, but had not made all the setup the first time, I did a new installation. Now I got the same problem! The box says there is nothing to boot from

I am stuck and do not know what to do!

Anyone has a clue whats going on?

Any help much appreciated!