Still having this problem with buster and newer hardware "Intel NUC8".
Sometimes the ahci module gets loaded without any modification of the installer (/bin/hw-detect). When using the old hack > d-i preseed/early_command string > sed -i '/^update-dev >.dev.null$/i udevadm control --reload' > /bin/hw-detect the ahci module seems to be loaded reliably. Jörg
