Looks like it doesn't boot at XMP settings or XMP is not enabled in BIOS. When you changed the CPU then almost for sure the motherboard used default settings. It should show it on the first screen after the CPU swap but it depends on the BIOS version and some other things. Simply enter BIOS, check if settings are correct, save them again and restart the PC.
Download standard CPU-Z version. You are using the one for really old hardware.