I also got the error, "Unable to perform deferred repairs without full space verification", when I ran Disk Utility (DU) on my Data volume.
I found a post that directed me to an Apple Support web page "How to repair a Mac disk with Disk Utility". The key point that you might gloss over when reading that page is to run DU several times, starting with the last/bottom volume in the list of volumes shown on the left (e.g. Macintosh HD - Data) and working your way up. This is probably the volume where you got your error when you ran DU (that's what happened to me).
Once you've run DU on the next volume (your system volume, e.g. Macintosh HD), the next step is what surprised me. Move to the text that says 'View' with a down-arrow that's just to the left of the words 'Disk Utility' in the top of the window and choose 'Show All Devices." This will reveal the 'Container' that your volumes are in, and the 'Media' (actual hard disk/SSD) in your computer.
Run DU on the Container first (which might take a long time), then run DU on the Media. Running it on the Container fixed my problem. I didn't find any problems on my Media. After that I ran DU on my 'Macintosh HD - Data' where I had gotten errors before and it had no errors. Hope this helps.