Didn't the device name change when you updated? I also have the same NVMe device and the name changed when updating to the initial v6.10.0-rc releases, it then changed back with -rc8 or later when it was corrected, if yours also changed and depending on how you handled that you might have wiped the device accidentally, symptom is consistent with wipefs being run on it, can't see how just upgrading would do that, but glad it's solved.