The error indicates the wrong exfat package is being used. GParted is written to use the exfatprogs [1] package, not the exfat-utils [2] one. These packages have different command line options.
[1] https://github.com/exfatprogs/exfatprogs [2] https://github.com/relan/exfat See upstream report [3]. [3] https://gitlab.gnome.org/GNOME/gparted/-/merge_requests/74 Curtis Gedak