some more details on my problem discussed above. Anyone have any ideas? I am looking for help to migrate from a 2012 Mac Pro with 4 internal HDD in Mac OS Extended Journaled (HFS+) to a MBP M1 connected to  a 4-6 slot external thunderbolt enclosure in JBOD mode(trying terramaster D5 now), which should hold my 3 HDD media drives formatted in HFS+ for heavy photo/video editing.  I don't want to use APFS for editing, should be HFS+.  drive bays for 1. boot clone overnight backup, 2. photos, 3. photos backup, 4. video, 5. video backup. No matter what I have tried, I cannot get brand new, or existing(formatted on mac pro, in HFS+ or in exFat) HDD's to mount or to be visible (in disk utility devices view) on my MBP m1 or on my 2017 iMac's.  I can get usb3.0/2.0 sticks to mount and function normally on both macs (MP and MBP).  below. details all HDD in mac pro( 10.12.6)  in HFS+ won't mount on MBP(11.5.3)  or iMac(10.15.7) on either the Terramaster thunderbolt D5 enclosure, or an Insignia NS-PCHDEDS19 usb 3.0 dual docking station(toaster). Confirmed drives powered/spinning in each case I can get a brand new Lacie 8TB HDD in exfat,bought from apple store, to mount on both macs( I copied my photos to this, but need to move them to a bare HDD in the enclosure next) I can get a usb3.0 in exFat to mount on both macs as a test I can get a usb 2.0 in fat16 to mount on both macs, and I was able to reformat this usb2.0 (on my mac pro) to HFS+ and it mounted later on the MBP, as a test A brand new 10TB Seagate HDD would not mount or show visible in disk utility(device view) in MBP.  On my mac pro, it was not recognized, but a pop up window allowed me to erase/reformat for apple/mac, so I reformatted to exFat.  Once reformatted to exFat, this 16T drive would not mount (not visible) through either enclosure on my MBP. Seems like a connectivity issue between 2 separate HDD enclosures with my Mac.  That seems hard to believe it is faulty hardware or cables from two separate vendors. Note the Lacie 8TB in exfat mounts to the MBP when connected as follows:    Lacie->(thunderbolt)-> terramaster enclosure->(thunderbolt)->MBP,  so the cabling/power from MBP through terramaster to Lacie is not the issue. One solution would be to find a source of new drives that will mount in both my mac pro and the MBP (like the Lacie) and copy all my data over in the mac pro from the existing drives to the new drives.  But this is expensive as i just bought 3 large drives for my media on the mac pro before starting this process. If I can't get my current HFS+ drives to work in the MBP/enclosure, next best option is to copy data on each HFS+ drive to the lacie in exFat, reformat old drive to HFS+ on the MBP(but MBP not mounting the existing drives), and transfer from lacie to reformatted drive on MBP/terramaster.  Time consuming, but less expensive than replacing drives. I Need help? I am hoping this is a simple sw/formatting issue and not a hw/drive issue.   If I need to return my terramaster hw, the mac website only has one option for RAID, prepopulated with expensive drives in nonoptimal capacities. Last resort. Any ideas?