How to merge the Fusion Drive into a Single Drive on macOS Monterey

Fusion drive is split. On the 24 GB SSD there's 21.5GB sitting there that used to have High Sierra. On the 1TB SATA is Monterey, eventually working, after climbing Everest to install it. All I want to do is merge the fusion drive into a single drive so that it functions as it should i.e. MacOS & frequently used files on the SSD & the rarely used stuff on the TB drive, working in harmony. I have Goggled & Apple'd solutions & rebooted the Mac & fed in more Terminal commands than I've ever done since computers were invented & the drive will not merge. On theMac, I am simply classed as 'User'& "diskutil resetfusion" or "resetFusion|" informs me that 'User' has blocked or stopped the command. How can I get around this issue? I have followed more useless advice from 'experts' & achieved the square root of zero over the last month, off & on. To rephrase, all I want is the fusion drive with Monterey yet it would seem to be easier to rebuild Rome from the ground up. An example was, on this Mac, I wanted to link FaceTime...then there's the Apple ID & to reset a single password...Apple will be in touch within 14 days....& this is all in the digital, high-speed age of nothing. It's quicker to get viable answers by post, pony express or semaphore. How is that possible?

[Re-Titled by Moderator]