I always use Gnome Disks to create a USB Stick and never had a problem with it, so maybe there is something in the way the Solus image is created.
I insert the USB Stick, then select it in Disks, then click the 3 dots in the upper right that appear, then select "Restore Disk Image".
Over the last few days I've installed Manjaro, blend OS, Debian 12, Pop OS, makulu and a couple of others, all with no issue and using 'Disks' to create the USB stick. So maybe there is an issue with the ISO itself.