Probably due to unmet dependencies:
purism@pureos:~$ sudo apt list phosh-core --installed
[sudo] password for purism:
phosh-core/now 24 arm64 [installed,upgradable to: 37]
Attempting to upgrade the package prints this output:
purism@pureos:~$ sudo apt upgrade phosh-core
Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created or been moved out of Incoming.
The following information may help to resolve the situation:
Unsatisfied dependencies:
phosh-core : Depends: gnome-control-center (>= 1:44) but 1:43.6-2~deb12u1pureos1 is to be installed
Depends: phoc (>= 0.37.0) but 0.33.0+ds-1pureos1 is to be installed
Depends: phosh (>= 0.37.0) but 0.34.0-2pureos1 is to be installed
Depends: phosh-mobile-tweaks (>= 0.37.0) but 0.34.0-2pureos1 is to be installed
Recommends: gnome-contacts (>= 44) but 43.1-1 is to be installed
Recommends: gnome-console (>= 44) but 43.0-2 is to be installed
Recommends: phog but it is not going to be installed
Recommends: phosh-mobile-settings (>= 0.37.0) but 0.34.0-1pureos1 is to be installed
Recommends: xdg-desktop-portal-wlr but it is not going to be installed
Error: Broken packages