I can also confirm Ministack STX can maintain a consistent connection with Silicon Macs (unlike many other HDD enclosures and some SSD enclosures, especially RAID boxes).
However, don't assume that connecting a problematic (with Big Sur-Monterey Mac) enclosure to Ministack STX will end its "unexpected ejections". In my experience, what doesn't stay connected directly won't stay connected through most "middlemen" devices. For example, the drive in the STX will remain connected but another drive attached to STX will still "unexpectedly eject" given enough time (minutes to hours for my hardware, whether sleep or not occurs).
Basically, the U in USB is no longer in play and external stuff attached to Big Sur-Monterey Macs is hit or miss in terms of avoiding the dreaded "unexpected ejections." I've worked through everything a user can and am almost entirely convinced the problem is with Big Sur and Monterey and only Apple debugging port connection software can fix it.
In the meantime, select stuff like STX seems to work as the U in USB implies. So the workaround is to try new hardware until you find something that works and wait out Apple getting around to debugging jack software in the OS to maybe get to return to reliable use of existing enclosures... OR downgrade back to a macOS BEFORE Big Sur and it will likely "just work" again.
Continuing to hope WWDC announces a year or two of Snow Monterey instead of piling on even more features and not getting rid of meaningful-impact bugs.
