exFAT and HFS+ drives not mounting

[crashintoty]

A client has just upgraded from an Intel MacBook Pro (2018) with 10.13.6/High Sierra to a M1 MacBook Pro (2021) with 12.3.1/Monterey. They have an exFAT formatted LaCie 2TB USB-C 2.5" external drive and a Mac OS Extended (Journaled) formatted Pegasus R4 Thunderbolt 1 external disk array (RAID5). These drives mount just fine on the Intel Mac, but won't mount on the M1 Mac. In fact, the LaCie appears to mount initially, but quickly unmounts and the notification message appears "disk not ejected properly" (even though it was ejected properly).

Any ideas on how to get these exFAT and MacOS Extended external drives mounted and functional on M1 macs?

 

[Fishrrman]

I realize this sounds simplistic, but...
- have you tried using a DIFFERENT connecting cable?
- have you tried using a USB hub between the drive and the MBP?

 

[crashintoty]

I realize this sounds simplistic, but...
- have you tried using a DIFFERENT connecting cable?
- have you tried using a USB hub between the drive and the MBP?

No, but there appears to be no chance that the cables are the problem. I've tried these external drives and their cables on 5 different MacBooks so far, ranging from 2012 to 2021, 10.13.6 to 12.3.1 and they mount on all the Intel Macs, but not the 2021 M1 MacBook Pro.

 

[lcubed]

have you checked for the latest drivers and firmware from pegasus?
i wouldn't be surprised if both were needed to operate on the M1 macs

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