was going to say you might find out which is with using ls -la /dev/disk/by-partuuid/ls -la /dev/disk/by-partuuid/ as those looked like partuuid but i was too late
personally at this point i would make a backup of BOOTX64.EFI in the windows efi and copy the refind.efi file to the same folder and rename it to BOOTX64.EFI to try force it to be the first choice, but idk if refind even will behave correctly then or break the boot, idk if you want to risk that as idk if i would recommend that as a "solution" for a computer. its more a workaround for USB boot installers
more that the person helping you has no access to their steamdeck atm so im helping you blindfolded on the steamdeck specifics and just from what i know about linux in general on anything else