Monterey keeps corrupting my external drive

Hi there,

I've found an interesting problem, and it seems like quite a few people are having similar problems online (although its always hard to tell if its exactly the same).

I use an external on my older mac (running Mojave) - everything works fine here, and I don't want to upgrade or change it as its a work machine and should remain there for opening old projects until years after this transition.

I've bought a new (refurb) m1 max Macbook Pro. It shipped with Monterey. Note that the Laptop only has USB C, and the old machine only has USB A - I didn't think this would be a problem as I could switch which adapter i'm using (and I also don't believe it IS the problem... see later).

When I plugged in my external drive (its a 4TB samsung 870 QVO - using a Sabrent ssd to USB A cable), it showed up initially, then gave me an error in finder (error code 32730 - no details online). I thought little of it - the hub was unpowered so I thought that may be the problem.

When I tried to plug it back into my old machine, it wouldn't mount. I tried everything, all sorts of Disk repairs, fsck, terminal stuff, whatever - the disk was corrupt. Disk Drill couldn't repair it either, so i resorted to using that to recover the files (I had a near backup, but was able to grab the newer files - no data lost now I think).

Once i'd got everything sorted again, I formatted the drive APFS on my old machine, put all the files back (took hours). I thought I'd try again - I'd just ordered a new SATA/SSD to USB C cable, so I wouldn't have to go through the hub. I also ordered a cable to power the hub. So there are 2 methods I can use to connect.

Long story short, neither techniques work. The drive formatted on my Mojave machine won't read, and WILL be corrupted by my M1 Monterey laptop.

Interestingly, if I format the drive in Monterey, its the same the other way around - It works fine in Monterey, but If I plug it in to my Mojave machine, it gets corrupt / "disk not recognised - do you want to initialise" etc.

It seems that switching the adapter could be causing the problem. Although that's somewhat disproved, as the problem still occurs if i stick with the USB A adapter, and use the powered Anker hub to plug it into the laptop.

It seems these two OSs are somehow incompatible, both with APFS and HFS. But importantly - they corrupt the drives!! If I upgrade to Ventura, will this not happen? I'm not sure! I'm ruling out a faulty drive for now, as its worked flawlessly until trying to use it on the laptop, and also works flawlessly after formatting (until i try to switch the machine its running on).

I've tried a lot of combinations. Here's a (sort of) log -

• Mojave drive corrupted by M1 Monterey by plugging in USB A via unpowered hub. Reformatted to APFS, all files put back
• Monterey corrupts the drive again, via USB C this time (switched the adapter). Not using hub, directly into the laptop
• Formatted the drive in Monterey - all works fine on the laptop - can use it and re-installed some lost programs. When plugging into the Mojave machine, it can't read/mount the drive (but hasn't corrupted it... yet).
• I'll likely have to format again now, as I need it to be usable on my old machine as that's where I'm working until I can reliable use the new machine with this SSD.

Does anyone know if there's known compatibility issues between these OSes? Should I upgrade the laptop to Ventura, hoping the USB bugs are gone?

Thanks for reading, it's a long one...