A 2019 Mac has no SSD, just some memory chips soldered to the logic board, thus you can’t go against APFS indications in any way.
Apple partition map scheme works only for older Macs, not your case: https://support.apple.com/guide/disk-utility/partition-schemes-dsku1c614201/mac
It seems like your Mac has a board failure since there’s no user replaceable hard drive. Try using a different OS if you can get somehow a bootable pendrive from a friend, just in case. In case that fails too, you got a logic board issue, that needs repair or replacement.