SSD no longer recognized after Disk Utility erase
I have a 15” late-2016 MacBook Pro that I had used daily since I bought it in 2017. I was trying to wipe the drive as I had just sold it online, so was following Apple’s online guide to preparing it for sale. https://support.apple.com/en-us/HT201065
I got to step 7 and followed the instructions here to erase the drive. https://support.apple.com/en-us/HT208496
When disk utility finished, it restarted and showed a circle with a line through it. Being somewhat tech savvy, I booted into internet recovery but found in Disk Utility there was no SSD listed. So I made bootable copies of Big Sur and High Sierra and loaded Disk Utility through those and still no device or volume listed. I tried using Disk Utility Terminal commands to see if anything was listed, and nothing was listed that should have represented the 512GB drive.
I can’t figure it out.. and the techs at Apple are bemused. Apple is now saying the SSD needs to be replaced. I literally followed their instructions, and now they’re asking me for $680 to fix it!? Is this a known problem with old Apple SSD’s, APFS, and Disk Utility? Does this sound familiar to anyone? TIA!!