restored the functionality (note /var/lib/apt/extended_states had 5732 lines and it was narrowed down to this one)
FYI:
ii python3-update-manager 1:20.04.10.1 all python 3.x module for update-manager
ii update-manager 1:20.04.10.1 all GNOME application that manages apt updates
ii update-manager-core 1:20.04.10.1 all manage release upgrades
Through a process of trial and error - removing the following from /var/lib/ apt/extended_ states
Package: gnome-software- plugin- snap
Architecture: amd64
Auto-Installed: 1
restored the functionality (note /var/lib/ apt/extended_ states had 5732 lines and it was narrowed down to this one) update- manager 1:20.04.10.1 all python 3.x module for update-manager
FYI:
ii python3-
ii update-manager 1:20.04.10.1 all GNOME application that manages apt updates
ii update-manager-core 1:20.04.10.1 all manage release upgrades