Disk transfer speed deterioration since installing Windows 11

Hi, I installed a clean 25H2 in a laptop on both a HDD and SSD (double work but a good experiment). Both worked perfectly. Then I removed all partitions on HD and cloned the SDD to the HDD. Once done, I configured the bios to boot the HDD; the disk ran at 100%. I went through all the mainstream steps to disable sysmain and windowss search, and , but the "clone action" of SDD to HDD changes something that is beyond the obvious. Perhaps others have taken the time to investigate this, but since it is a clean install with little else but a few basic apps such as DiskWizard, the 25H2 OS is doing something in the HDD clone that is not seen when booting the SSD. Open to ideas at this point. (BTW, same issue on four different laptops, so I took only one of the laptops to do a clean install to eliminate any long-term application issues.)