I had previously tested this dual boot on an older legacy BIOS PC, and it worked fine. I have a new Dell Precision 3660 with UEFI BIOS, with 2 x 1TB NVME drives. It came with Windows 11 installed, and I installed Ubuntu on the spare drive and it went fine. From BIOS, when I select Windows Boot Loader it starts to boot Windows but just sits with the spinning wheel and never actually boots into windows.The Windows 11 partition is still there but I just need to get the boot loader to recognise it.
Here is the link to the pastebin from Boot Repair
https://paste.ubuntu.com/p/n2HHD28fb3/
Any help is much appreciated!