Your rescue USB is newer than your server
I was rebuilding the boot disk of a NAS running Ubuntu 24.04 — kernel 6.8 — and doing the work from an Ubuntu 26.04 live USB, because that’s what I had on the Ventoy stick. This felt fine. A newer rescue environment is usually a better rescue environment: more recent tooling, drivers for newer hardware, fewer bugs. The plan was a mirrored encrypted root: GPT, mdadm RAID1 across two SSDs, LUKS2 on top, LVM inside. I created the array degraded on the new disk, put LUKS2 on it, made the volume group, copied 262 GB of root filesystem across, set up systemd-boot, and rebooted. ...