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I've been having the same problem with my new Mac Mini M4 and OWC Express 1M2.

I had over a dozen kernel panics before I realised it was the 1M2 causing the problem:

/Library/Logs/DiagnosticReports/panic-etc...
> panic(cpu 4 caller 0xfffffe003d0656b8): busy timeout[0], (60s): 'pci1c5c,174a' (a,4020001) @IOService.cpp:5829

Since then, the partition doesn't seem to get recognised when I plug it into the TB4 port. The device shows up under Thunderbolt/USB4 in system information app, but it does not show the partitions, and nothing is mounted in macos.

When I instead plug it into one of the USB-C ports (non-USB4/non-TB4), the drive is recognised fine.

I wonder if the ASM2464 is broken for USB4 connectivity... Unfortunately I don't have another USB4 drive or USB4/TB4 computer to test the 1M2 with.

Does anyone else have the same problem? i.e. doesn't work when connected via TB4/USB4 to macos, but does with plain USB-C?
 
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