It might also be worth ruling out low-level issues:
- Check for anything strange in the BIOS related to disks (fwupdmgr can automatically install BIOS updates from a live Linux session. I don’t know if Bazzite does this)
- Try using a different SATA port
- Run some SMART tests on your drives
Proliant G9 is an EoL server that hasn’t been sold since 2018. Meanwhile, Debian bookworm released last year. I’d be surprised if the problem were that your installer gave you a kernel that’s too old.
What is the output of
ip addr show
?