Just wanted to clarify here that the issue of a power reset/cycle during a large write, so far, has shown to be operating system and USB NVME chipset agnostic. It’s at least because of some FW AMD mainboard/SSD incompatibility. A possible reason is that the system is not giving enough power to certain SSDs during sustained high speed write. Perhaps some power hungrier SSD models ask for power but don’t receive it fast enough or at all, which causes them to reset. This happens negotiated at 10Gbps speeds. It doesn’t reset when forcing negotiation at USB2/480Mbps or when the system mistakenly negotiates a 5Gbps connection on one (perhaps some) of the ports.
@Adrian_Joachim are you testing a large sustained write when negotiated at 10Gbps? A full 10GB transfer should reliably reproduce the issue. Your/the ASMedia 246x has reports of being pretty stable AFAIK, so if you can repro it then it further excludes USB NVME chipsets from being the culprit. If, indeed, large writes work on Windows but not Linux, with your ASMedia 246x and Samsung 970 Evo, then that’s some potentially revealing info.
Edit: also to add, we still don’t know if this issue affects all mainboards or just a specific batch, if it’s fixable in software, etc.
Echoing @Jason_Username_Taken that it would be nice if FW was publicly tracking/commenting on this issue, but some good news is that I do have a support ticket open with them and they’ve acknowledged that “this issue is currently under active investigation”.