Without knowing all the technical details of the situation, I have been made aware that the USB hardware on the pi 4 doesn't like some cables. One youtuber tried about half a dozen different cables to various SSDs. (They did the same thing with power cables, btw). Not all the usb to ssd cables worked, to the pi 4, even if they worked on other computers. I regret that I do not recall which out of many youtubes and blogs detailed this. But the approach was summarized to the simple, "try a few different brand cables". One youtuber went further and modified the USB end of the cable and got it to work in some situations with some SSDs.
Personally, although I like to know exactly what is going on, so I can contribute the detail(s) with confidence to others, another part of me is becoming more easily content with knowing "brand x cable is problematic, while brand y cable has not manifested the same problem, and brand z might work with some drives if you modify the usb end wiring.". Back in the days when Apple was using SCSI drives and chains, that could become a wild ride matching and arranging proper cables and active or passive terminators to keep everything humming and showing up properly on a moderate to long SCSI chain. It wasn't an Apple problem, but an issue that manifested with cables, terminators, device combinations, and depending on the EMI environment. It was not a simple SCSI ID issue, although those days certainly did give rise to the popularity of the SCSI_probe tool(s). SCSI was fast in those pre-USB3 and Firewire etc days.
If anyone has encountered a cable as a solution, with a Pi 4 and an SSD, please say so, and the SSD brand/model and cable that worked. It could prove to be helpful, not to slam a cable or device manufacturer, but to understand that such issues can manifest when any piece in the hardware picture is not quite following quite the same 'spec' -- fully, or, is the victim of some unique EMI or power environment.
Thinking simple first, a cable swap is relatively painless,with all power off of course, and properly spec'd. And inspect and be careful with those cable connectors and contacts.