Except that your SSD DOES still have Windows on it, most likely, or at least the hidden boot and EFI system partitions.
When you "transfered everything over and reformatted my ssd" did you transfer ONLY the C: partition to the M.2 drive, or did you transfer ALL of the partitions from the old SSD to the new one? And when you "formatted the ssd", did you just format the existing C: drive that Windows was on or did you also delete the existing hidden partitions that Windows uses in order to know how to initialize the connected hardware and boot into the operating system?
Probably you are going to need to create bootable media for one of the partition management applications like Paragon partition manager, and do some work. It MIGHT be possible to copy the boot and EFI system partitions from the SSD to the M.2 drive, but if they are no longer there then you are likely going to have to do a full clean install of Windows to the M.2 drive, with the old SSD disconnected from the system until after the installation.