On Wednesday, 15 June 2022 03:00:16 BST Peter Humphrey wrote:
> Something else also changes at the first reboot after creating a new user
> account: a dialogue box opens requesting permission to mount a partition -
> but that partition is one of several marked 'noauto' in fstab. (Screen shot
> attached.)
> 
> What can possibly live under /home/prh and cause all this disruption? I
> might suspect I'd been hacked, but I've rebuilt a new system several times,
> and I've lost count of the times I've thrown away my user account and
> started again.

As it has already been commented the udisks points to desktop automounting 
function doing its thing here.  There a number of options to configure for all 
devices and selected devices.  However, I can't recall this pop up on new user 
accounts here, but I do not run any nvme devices to know if it is any 
different.