OK, I will check the commits in Calamares where they changed the disk setup, this is clearly a regression for XFS filesystems.
I think I have enough info now to replicate the issue here. If you want to get this install to work now, you can do a few things. Prep the disk before starting calamares with partitonmanager. Redo the whole setup, starting with setting the partition table (still use ms-dos). Then in calamares use either manual, or automated > replace and let it only adjust the already formatted sda1. Before starting the installer, make sure to run the grub-probe command again on sda1, don't try to install if it does not return xfs.
Or install with using ext4, I suspect the fail is only done toward xfs, since upstream does not test xfs changes.