Sorry for delay, I was not able to have Mac Pro switched on for hours.So folks with Sonnet cards... which slot is it installed in... I'm wondering the x8 slots are behind a PCI switch, and Sonnet's cards have a PCI bridge chip to allocate lanes between the SSDs... could that doubling up of lane negotiating infrastructure be the problem?
Is there anyone with a single SSD (as in only hosts 1) card exhibiting this behaviour?
Once opened, I discovered a thing that I forgot: Inside there were 2 Sonnet cards. One for SSD MVME, the other card is a Sonnet for SSD Sata III, which I used in the old Mac Pro. This card was mounted some year ago on the 5th slot, but it is empty, no HD. So I unmount this card. Tried to boot: I unmounted the Sonnet card NVME, installed on the 4th bay 16X, because Sonoma did it again. So this time I moved the Sonnet card on the 5th 16X slot: now seems that, this time, disconnections have decreased. It's the only card installed on the Mac Pro: I also have the Pegasus enclosure with 2 HDD Sata III 3,5 installed on top.
Anyway, the Sonnet card sometimes randomly disconnect.
Hoping that the next Sonoma update can solve this terrible bug, but I'm not so confident about it